diff --git a/runtime/Sim.Data/Engine/Translator.cs b/runtime/Sim.Data/Engine/Translator.cs
index 8c062de..e8c27df 100644
--- a/runtime/Sim.Data/Engine/Translator.cs
+++ b/runtime/Sim.Data/Engine/Translator.cs
@@ -802,9 +802,10 @@ internal sealed class Translator
         }
     }
 
-    /// <summary>DATEADD(day, ...) 的第一个参数是关键字，解析成列名</summary>
+    /// <summary>DATEADD(day, ...) 的第一个参数是关键字：ScriptDom 解析成 IdentifierLiteral（旧版本是列名）</summary>
     private static string DatePartName(ScalarExpression expression) => expression switch
     {
+        IdentifierLiteral i => i.Value,
         ColumnReferenceExpression c => c.MultiPartIdentifier.Identifiers[^1].Value,
         StringLiteral s => s.Value,
         _ => throw SqlException.NotSupported("这种 datepart 写法"),
diff --git a/runtime/Sim.WinForms/Host/SimHost.cs b/runtime/Sim.WinForms/Host/SimHost.cs
index cac9264..43da78b 100644
--- a/runtime/Sim.WinForms/Host/SimHost.cs
+++ b/runtime/Sim.WinForms/Host/SimHost.cs
@@ -134,12 +134,54 @@ public static class SimHost
     public static void ReportException(Exception ex)
     {
         while (ex is TargetInvocationException { InnerException: not null } wrapper) ex = wrapper.InnerException!;
-        Send(new JsonObject
+        var type = ex.GetType().FullName;
+        // 仿真库自己抛的异常信息已经是中文；.NET 自带的是英文，常见的几种配上中文说明，原文放在括号里
+        var message = HasChinese(ex.Message) ? $"{ex.Message}（{type}）"
+            : ExplainException(ex) is { } explained ? $"{explained}（{type}: {ex.Message}）"
+            : $"{type}: {ex.Message}";
+        var frame = StudentFrame(ex);
+        var result = new JsonObject
         {
             ["type"] = "exception",
-            ["message"] = $"{ex.GetType().FullName}: {ex.Message}",
-            ["detail"] = StudentStackTrace(ex),
-        });
+            ["message"] = message,
+            ["detail"] = frame is { } f ? $"出错位置：{f.File} 第 {f.Line} 行（{f.Method} 方法）" : StudentStackTrace(ex),
+        };
+        if (frame is { } at)
+        {
+            result["file"] = at.File;
+            result["line"] = at.Line;
+        }
+        Send(result);
+    }
+
+    private static bool HasChinese(string text) => text.Any(c => c >= '\u4e00' && c <= '\u9fff');
+
+    private static string? ExplainException(Exception ex) => ex switch
+    {
+        FormatException => "文字转换成数字或日期时格式不对，比如文本框是空的，或者里面不是数字",
+        NullReferenceException => "用到的对象是 null：变量还没有赋值，或者对象、窗体还没有 new 出来",
+        IndexOutOfRangeException => "数组的下标超出了范围：下标从 0 开始，最大是长度减 1",
+        ArgumentOutOfRangeException => "下标或参数超出了范围，比如列表、字符串的下标太大，或者下拉框还没有选中",
+        DivideByZeroException => "整数除以了 0",
+        OverflowException => "数字太大或太小，超出了这个类型能表示的范围",
+        InvalidCastException => "类型转换失败，这个对象不能转换成要求的类型",
+        KeyNotFoundException => "字典里没有这个键",
+        FileNotFoundException => "找不到这个文件",
+        DirectoryNotFoundException => "找不到这个文件夹",
+        _ => null,
+    };
+
+    /// <summary>堆栈里离出错点最近的一行学生代码：文件名、行号、方法名</summary>
+    private static (string File, int Line, string Method)? StudentFrame(Exception ex)
+    {
+        foreach (var frame in new System.Diagnostics.StackTrace(ex, true).GetFrames())
+        {
+            var file = frame.GetFileName();
+            var line = frame.GetFileLineNumber();
+            if (file == null || line <= 0 || file.Contains("/runtime/Sim.")) continue;
+            return (Path.GetFileName(file), line, frame.GetMethod()?.Name ?? "");
+        }
+        return null;
     }
 
     /// <summary>只保留学生代码的堆栈行，去掉仿真库内部的调用</summary>
diff --git a/samples/p6-t3-按时间查询/checks.yaml b/samples/p6-t3-按时间查询/checks.yaml
index 9f02cae..964a5f8 100644
--- a/samples/p6-t3-按时间查询/checks.yaml
+++ b/samples/p6-t3-按时间查询/checks.yaml
@@ -1,7 +1,7 @@
 # 评分规则：书上评价表的功能项。每项单独启动一次程序（使用 database.sql 建的初始数据库），按步骤操作，核对结果。
 # 初始数据有 3 行：2024-01-16 09:00、2024-01-18 14:30、2024-01-23 08:15
 # 格式说明见 server/src/grading/checks.ts
-- title: 能实现按日期查询灾情数据
+- title: 能实现按日期查询环境数据
   steps:
     - pick: { control: StartTime, value: '2024-01-15' }
     - pick: { control: EndTime, value: '2024-01-20' }
diff --git a/samples/p8-t3-环境采集与分析/database.sql b/samples/p8-t3-环境采集与分析/database.sql
index 2e5eeba..9d8b460 100644
--- a/samples/p8-t3-环境采集与分析/database.sql
+++ b/samples/p8-t3-环境采集与分析/database.sql
@@ -1,5 +1,5 @@
 -- 实验的初始数据库 WisdomCampus（教材"综合实训"附带的库）：环境数据表 EnvironmentData、报警图片表 SecurityData、用户表 Users。
--- EnvironmentData 预置了 7 天的历史数据，"数据分析"的图表一打开就有内容；SecurityData 是空的，拍照或有人入侵时才有记录。
+-- EnvironmentData 预置了今天之前 7 天的历史数据（按建库那天往前推），"数据分析"的图表一打开就有最近一周的内容；SecurityData 是空的，拍照或有人入侵时才有记录。
 -- 学生可以在数据库页面"恢复实验初始数据"；评分时每个检查项用一份新的。
 CREATE DATABASE WisdomCampus
 GO
@@ -10,45 +10,45 @@ CREATE TABLE EnvironmentData (Id int IDENTITY(1,1) PRIMARY KEY, Fire bit NOT NUL
 CREATE TABLE SecurityData (Id int IDENTITY(1,1) PRIMARY KEY, EvenTime datetime NOT NULL, EvenImage image NOT NULL)
 GO
 INSERT INTO Users (UserName, Password) VALUES ('admin', '123')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 58, 258, '2026-10-14 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.1, 53, 475, '2026-10-14 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 761, '2026-10-14 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.5, 49, 733, '2026-10-14 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 54, 528, '2026-10-14 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 283, '2026-10-14 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.9, 59, 261, '2026-10-15 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 53, 499, '2026-10-15 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 764, '2026-10-15 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.5, 47, 778, '2026-10-15 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 503, '2026-10-15 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 56, 218, '2026-10-15 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 13.9, 63, 258, '2026-10-16 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 60, 477, '2026-10-16 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 741, '2026-10-16 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.5, 54, 796, '2026-10-16 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 488, '2026-10-16 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 59, 214, '2026-10-16 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 11.9, 67, 234, '2026-10-17 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 63, 544, '2026-10-17 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.3, 60, 804, '2026-10-17 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.5, 54, 801, '2026-10-17 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.8, 59, 524, '2026-10-17 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 58, 286, '2026-10-17 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.4, 59, 250, '2026-10-18 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 55, 533, '2026-10-18 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.3, 50, 749, '2026-10-18 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 24, 48, 766, '2026-10-18 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.8, 54, 534, '2026-10-18 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.1, 53, 241, '2026-10-18 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.4, 54, 253, '2026-10-19 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.1, 50, 474, '2026-10-19 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.3, 48, 778, '2026-10-19 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 26, 46, 783, '2026-10-19 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.3, 50, 520, '2026-10-19 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.6, 50, 213, '2026-10-19 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 62, 230, '2026-10-20 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.6, 52, 471, '2026-10-20 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 53, 751, '2026-10-20 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.5, 48, 747, '2026-10-20 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 527, '2026-10-20 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 220, '2026-10-20 18:00:00')
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 58, 258, DATEADD(hour, 8, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.1, 53, 475, DATEADD(hour, 10, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 761, DATEADD(hour, 12, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.5, 49, 733, DATEADD(hour, 14, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 54, 528, DATEADD(hour, 16, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 283, DATEADD(hour, 18, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.9, 59, 261, DATEADD(hour, 8, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 53, 499, DATEADD(hour, 10, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 764, DATEADD(hour, 12, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.5, 47, 778, DATEADD(hour, 14, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 503, DATEADD(hour, 16, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 56, 218, DATEADD(hour, 18, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 13.9, 63, 258, DATEADD(hour, 8, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 60, 477, DATEADD(hour, 10, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 741, DATEADD(hour, 12, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.5, 54, 796, DATEADD(hour, 14, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 488, DATEADD(hour, 16, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 59, 214, DATEADD(hour, 18, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 11.9, 67, 234, DATEADD(hour, 8, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 63, 544, DATEADD(hour, 10, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.3, 60, 804, DATEADD(hour, 12, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.5, 54, 801, DATEADD(hour, 14, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.8, 59, 524, DATEADD(hour, 16, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 58, 286, DATEADD(hour, 18, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.4, 59, 250, DATEADD(hour, 8, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 55, 533, DATEADD(hour, 10, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.3, 50, 749, DATEADD(hour, 12, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 24, 48, 766, DATEADD(hour, 14, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.8, 54, 534, DATEADD(hour, 16, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.1, 53, 241, DATEADD(hour, 18, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.4, 54, 253, DATEADD(hour, 8, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.1, 50, 474, DATEADD(hour, 10, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.3, 48, 778, DATEADD(hour, 12, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 26, 46, 783, DATEADD(hour, 14, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.3, 50, 520, DATEADD(hour, 16, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.6, 50, 213, DATEADD(hour, 18, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 62, 230, DATEADD(hour, 8, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.6, 52, 471, DATEADD(hour, 10, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 53, 751, DATEADD(hour, 12, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.5, 48, 747, DATEADD(hour, 14, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 527, DATEADD(hour, 16, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 220, DATEADD(hour, 18, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
diff --git a/samples/p8-t4-校园安防/database.sql b/samples/p8-t4-校园安防/database.sql
index 2e5eeba..9d8b460 100644
--- a/samples/p8-t4-校园安防/database.sql
+++ b/samples/p8-t4-校园安防/database.sql
@@ -1,5 +1,5 @@
 -- 实验的初始数据库 WisdomCampus（教材"综合实训"附带的库）：环境数据表 EnvironmentData、报警图片表 SecurityData、用户表 Users。
--- EnvironmentData 预置了 7 天的历史数据，"数据分析"的图表一打开就有内容；SecurityData 是空的，拍照或有人入侵时才有记录。
+-- EnvironmentData 预置了今天之前 7 天的历史数据（按建库那天往前推），"数据分析"的图表一打开就有最近一周的内容；SecurityData 是空的，拍照或有人入侵时才有记录。
 -- 学生可以在数据库页面"恢复实验初始数据"；评分时每个检查项用一份新的。
 CREATE DATABASE WisdomCampus
 GO
@@ -10,45 +10,45 @@ CREATE TABLE EnvironmentData (Id int IDENTITY(1,1) PRIMARY KEY, Fire bit NOT NUL
 CREATE TABLE SecurityData (Id int IDENTITY(1,1) PRIMARY KEY, EvenTime datetime NOT NULL, EvenImage image NOT NULL)
 GO
 INSERT INTO Users (UserName, Password) VALUES ('admin', '123')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 58, 258, '2026-10-14 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.1, 53, 475, '2026-10-14 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 761, '2026-10-14 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.5, 49, 733, '2026-10-14 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 54, 528, '2026-10-14 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 283, '2026-10-14 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.9, 59, 261, '2026-10-15 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 53, 499, '2026-10-15 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 764, '2026-10-15 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.5, 47, 778, '2026-10-15 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 503, '2026-10-15 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 56, 218, '2026-10-15 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 13.9, 63, 258, '2026-10-16 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 60, 477, '2026-10-16 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 741, '2026-10-16 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.5, 54, 796, '2026-10-16 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 488, '2026-10-16 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 59, 214, '2026-10-16 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 11.9, 67, 234, '2026-10-17 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 63, 544, '2026-10-17 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.3, 60, 804, '2026-10-17 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.5, 54, 801, '2026-10-17 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.8, 59, 524, '2026-10-17 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 58, 286, '2026-10-17 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.4, 59, 250, '2026-10-18 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 55, 533, '2026-10-18 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.3, 50, 749, '2026-10-18 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 24, 48, 766, '2026-10-18 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.8, 54, 534, '2026-10-18 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.1, 53, 241, '2026-10-18 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.4, 54, 253, '2026-10-19 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.1, 50, 474, '2026-10-19 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.3, 48, 778, '2026-10-19 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 26, 46, 783, '2026-10-19 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.3, 50, 520, '2026-10-19 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.6, 50, 213, '2026-10-19 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 62, 230, '2026-10-20 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.6, 52, 471, '2026-10-20 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 53, 751, '2026-10-20 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.5, 48, 747, '2026-10-20 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 527, '2026-10-20 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 220, '2026-10-20 18:00:00')
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 58, 258, DATEADD(hour, 8, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.1, 53, 475, DATEADD(hour, 10, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 761, DATEADD(hour, 12, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.5, 49, 733, DATEADD(hour, 14, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 54, 528, DATEADD(hour, 16, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 283, DATEADD(hour, 18, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.9, 59, 261, DATEADD(hour, 8, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 53, 499, DATEADD(hour, 10, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 764, DATEADD(hour, 12, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.5, 47, 778, DATEADD(hour, 14, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 503, DATEADD(hour, 16, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 56, 218, DATEADD(hour, 18, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 13.9, 63, 258, DATEADD(hour, 8, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 60, 477, DATEADD(hour, 10, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 741, DATEADD(hour, 12, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.5, 54, 796, DATEADD(hour, 14, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 488, DATEADD(hour, 16, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 59, 214, DATEADD(hour, 18, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 11.9, 67, 234, DATEADD(hour, 8, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 63, 544, DATEADD(hour, 10, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.3, 60, 804, DATEADD(hour, 12, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.5, 54, 801, DATEADD(hour, 14, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.8, 59, 524, DATEADD(hour, 16, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 58, 286, DATEADD(hour, 18, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.4, 59, 250, DATEADD(hour, 8, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 55, 533, DATEADD(hour, 10, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.3, 50, 749, DATEADD(hour, 12, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 24, 48, 766, DATEADD(hour, 14, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.8, 54, 534, DATEADD(hour, 16, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.1, 53, 241, DATEADD(hour, 18, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.4, 54, 253, DATEADD(hour, 8, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.1, 50, 474, DATEADD(hour, 10, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.3, 48, 778, DATEADD(hour, 12, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 26, 46, 783, DATEADD(hour, 14, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.3, 50, 520, DATEADD(hour, 16, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.6, 50, 213, DATEADD(hour, 18, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 62, 230, DATEADD(hour, 8, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.6, 52, 471, DATEADD(hour, 10, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 53, 751, DATEADD(hour, 12, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.5, 48, 747, DATEADD(hour, 14, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 527, DATEADD(hour, 16, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 220, DATEADD(hour, 18, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
diff --git a/samples/p8-t5-历史图片/database.sql b/samples/p8-t5-历史图片/database.sql
index 2e5eeba..9d8b460 100644
--- a/samples/p8-t5-历史图片/database.sql
+++ b/samples/p8-t5-历史图片/database.sql
@@ -1,5 +1,5 @@
 -- 实验的初始数据库 WisdomCampus（教材"综合实训"附带的库）：环境数据表 EnvironmentData、报警图片表 SecurityData、用户表 Users。
--- EnvironmentData 预置了 7 天的历史数据，"数据分析"的图表一打开就有内容；SecurityData 是空的，拍照或有人入侵时才有记录。
+-- EnvironmentData 预置了今天之前 7 天的历史数据（按建库那天往前推），"数据分析"的图表一打开就有最近一周的内容；SecurityData 是空的，拍照或有人入侵时才有记录。
 -- 学生可以在数据库页面"恢复实验初始数据"；评分时每个检查项用一份新的。
 CREATE DATABASE WisdomCampus
 GO
@@ -10,45 +10,45 @@ CREATE TABLE EnvironmentData (Id int IDENTITY(1,1) PRIMARY KEY, Fire bit NOT NUL
 CREATE TABLE SecurityData (Id int IDENTITY(1,1) PRIMARY KEY, EvenTime datetime NOT NULL, EvenImage image NOT NULL)
 GO
 INSERT INTO Users (UserName, Password) VALUES ('admin', '123')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 58, 258, '2026-10-14 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.1, 53, 475, '2026-10-14 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 761, '2026-10-14 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.5, 49, 733, '2026-10-14 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 54, 528, '2026-10-14 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 283, '2026-10-14 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.9, 59, 261, '2026-10-15 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 53, 499, '2026-10-15 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 764, '2026-10-15 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.5, 47, 778, '2026-10-15 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 503, '2026-10-15 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 56, 218, '2026-10-15 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 13.9, 63, 258, '2026-10-16 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 60, 477, '2026-10-16 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 741, '2026-10-16 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.5, 54, 796, '2026-10-16 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 488, '2026-10-16 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 59, 214, '2026-10-16 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 11.9, 67, 234, '2026-10-17 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 63, 544, '2026-10-17 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.3, 60, 804, '2026-10-17 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.5, 54, 801, '2026-10-17 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.8, 59, 524, '2026-10-17 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 58, 286, '2026-10-17 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.4, 59, 250, '2026-10-18 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 55, 533, '2026-10-18 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.3, 50, 749, '2026-10-18 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 24, 48, 766, '2026-10-18 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.8, 54, 534, '2026-10-18 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.1, 53, 241, '2026-10-18 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.4, 54, 253, '2026-10-19 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.1, 50, 474, '2026-10-19 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.3, 48, 778, '2026-10-19 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 26, 46, 783, '2026-10-19 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.3, 50, 520, '2026-10-19 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.6, 50, 213, '2026-10-19 18:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 62, 230, '2026-10-20 08:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.6, 52, 471, '2026-10-20 10:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 53, 751, '2026-10-20 12:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.5, 48, 747, '2026-10-20 14:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 527, '2026-10-20 16:00:00')
-INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 220, '2026-10-20 18:00:00')
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 58, 258, DATEADD(hour, 8, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.1, 53, 475, DATEADD(hour, 10, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 761, DATEADD(hour, 12, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.5, 49, 733, DATEADD(hour, 14, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 54, 528, DATEADD(hour, 16, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 283, DATEADD(hour, 18, DATEADD(day, -7, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.9, 59, 261, DATEADD(hour, 8, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 53, 499, DATEADD(hour, 10, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 764, DATEADD(hour, 12, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.5, 47, 778, DATEADD(hour, 14, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.8, 52, 503, DATEADD(hour, 16, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 56, 218, DATEADD(hour, 18, DATEADD(day, -6, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 13.9, 63, 258, DATEADD(hour, 8, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 60, 477, DATEADD(hour, 10, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.8, 51, 741, DATEADD(hour, 12, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.5, 54, 796, DATEADD(hour, 14, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 488, DATEADD(hour, 16, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.6, 59, 214, DATEADD(hour, 18, DATEADD(day, -5, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 11.9, 67, 234, DATEADD(hour, 8, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 63, 544, DATEADD(hour, 10, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.3, 60, 804, DATEADD(hour, 12, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.5, 54, 801, DATEADD(hour, 14, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.8, 59, 524, DATEADD(hour, 16, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.1, 58, 286, DATEADD(hour, 18, DATEADD(day, -4, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 16.4, 59, 250, DATEADD(hour, 8, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.6, 55, 533, DATEADD(hour, 10, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.3, 50, 749, DATEADD(hour, 12, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 24, 48, 766, DATEADD(hour, 14, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.8, 54, 534, DATEADD(hour, 16, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.1, 53, 241, DATEADD(hour, 18, DATEADD(day, -3, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.4, 54, 253, DATEADD(hour, 8, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.1, 50, 474, DATEADD(hour, 10, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 22.3, 48, 778, DATEADD(hour, 12, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 26, 46, 783, DATEADD(hour, 14, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 23.3, 50, 520, DATEADD(hour, 16, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 20.6, 50, 213, DATEADD(hour, 18, DATEADD(day, -2, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 15.9, 62, 230, DATEADD(hour, 8, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 18.6, 52, 471, DATEADD(hour, 10, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 53, 751, DATEADD(hour, 12, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 21.5, 48, 747, DATEADD(hour, 14, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 19.3, 55, 527, DATEADD(hour, 16, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
+INSERT INTO EnvironmentData (Fire, Smoke, Temperature, Humidity, Light, _Time) VALUES (0, 0, 17.1, 57, 220, DATEADD(hour, 18, DATEADD(day, -1, CONVERT(varchar(10), GETDATE(), 120))))
diff --git a/server/test/runner.test.ts b/server/test/runner.test.ts
index 3df6df1..77d74d9 100644
--- a/server/test/runner.test.ts
+++ b/server/test/runner.test.ts
@@ -806,3 +806,44 @@ test.skipIf(config.sandbox === 'none')(
   },
   30000,
 )
+
+test('运行时异常：常见的 .NET 异常配中文说明，带出错的文件、行号和方法', async () => {
+  const { runner } = await runMain(
+    'exception',
+    `
+        Console.WriteLine("start");
+        int n = int.Parse("abc");`,
+  )
+  const error = await runner.next('exception')
+  expect(error.message).toStartWith('文字转换成数字或日期时格式不对')
+  expect(error.message).toContain('System.FormatException')
+  expect(error).toMatchObject({ file: 'Program.cs', line: 11 })
+  expect(error.detail).toBe('出错位置：Program.cs 第 11 行（Main 方法）')
+}, 30000)
+
+test('数据库：DATEADD、DATEDIFF、DATEPART 的日期单位写成关键字（day、hour）', async () => {
+  const dbDir = resolve(ROOT, '.runs', 'test-dateadd-db')
+  await rm(dbDir, { recursive: true, force: true })
+  await mkdir(dbDir, { recursive: true })
+  const { runner } = await runMain(
+    'dateadd',
+    `
+        var master = new SqlConnection("Data Source=.;User ID=sa");
+        master.Open();
+        new SqlCommand("CREATE DATABASE T", master).ExecuteNonQuery();
+        var conn = new SqlConnection("Data Source=.;Initial Catalog=T");
+        conn.Open();
+        foreach (var sql in new[] {
+            "SELECT DATEADD(hour, 8, DATEADD(day, -7, '2024-01-16'))",
+            "SELECT DATEDIFF(day, '2024-01-01 23:00', '2024-01-02 01:00')",
+            "SELECT DATEPART(hh, '2024-01-16 09:05:03')",
+        })
+            Console.WriteLine("result=" + new SqlCommand(sql, conn).ExecuteScalar());`,
+    'using System.Data.SqlClient;',
+    dbDir,
+  )
+  await runner.finished()
+  const output = runner.messages.flatMap((m) => (m.type === 'console' ? [m.text] : [])).join('')
+  expect(runner.messages.filter((m) => m.type === 'exception')).toEqual([])
+  expect(output).toBe('result=2024/1/9 8:00:00\nresult=1\nresult=9\n')
+}, 30000)
diff --git a/shared/protocol.ts b/shared/protocol.ts
index 37d711c..7554503 100644
--- a/shared/protocol.ts
+++ b/shared/protocol.ts
@@ -120,7 +120,8 @@ export type RunnerMessage =
   /** 学生程序操作了实训台输出：led/text、adam4150/do、zigbee/relay、camera/on、camera/pan，data 见 DeviceCtrlHelper.cs、IPCameraHelper.cs */
   | { type: 'device'; device: string; action: string; data: unknown }
   | { type: 'console'; text: string }
-  | { type: 'exception'; message: string; detail: string }
+  /** 学生程序没有处理的异常；file、line 是出错的那行学生代码（找得到时才有），网页上点击可以跳过去 */
+  | { type: 'exception'; message: string; detail: string; file?: string; line?: number }
   | { type: 'exited'; code: number }
 
 /**
diff --git a/web/src/auth.ts b/web/src/auth.ts
index bd25ec9..559cee8 100644
--- a/web/src/auth.ts
+++ b/web/src/auth.ts
@@ -26,6 +26,7 @@ export async function login(username: string, password: string) {
   const result = await api<Tokens & { user: User }>('POST', '/api/login', { username, password })
   setTokens(result)
   currentUser.value = result.user
+  return result.user
 }
 
 export async function logout() {
diff --git a/web/src/designer/FormDesigner.vue b/web/src/designer/FormDesigner.vue
index d04af06..913a6cb 100644
--- a/web/src/designer/FormDesigner.vue
+++ b/web/src/designer/FormDesigner.vue
@@ -373,15 +373,24 @@ function onDrop(event: DragEvent) {
   place(d, controlDef(type), x, y)
 }
 
-/** 双击工具箱：放在选中的容器（或窗体）左上角 */
+/** 双击工具箱：放在选中的容器（选中的是普通控件时放进它所在的容器）左上角，已有控件在那里就往右下错开 */
 function onToolDoubleClick(def: ControlDef) {
   const d = parsed.value.doc
   if (!d) return
-  // 直接放进选中的容器，不按坐标判断（左上角可能正好压在另一个分组框上）
-  const container = !def.component && selected.value && isContainerType(typeOf(d, selected.value) ?? '') ? selected.value : ''
-  const result = addControl(d, def, container, { x: 12, y: container ? 20 : 12 })
+  // 直接放进容器，不按坐标判断（左上角可能正好压在另一个分组框上）
+  let container = ''
+  if (!def.component && selected.value) {
+    container = isContainerType(typeOf(d, selected.value) ?? '') ? selected.value : (listControls(d).find((c) => c.name === selected.value)?.parent ?? '')
+  }
+  const location = { x: 12, y: container ? 20 : 12 }
+  const taken = childrenOf(d, container).map((child) => localRect(d, child))
+  while (taken.some((r) => r.x === location.x && r.y === location.y)) {
+    location.x += 12
+    location.y += 12
+  }
+  const result = addControl(d, def, container, location)
   selected.value = result.name
-  commit(result.doc)
+  commit(fitInside(result.doc, result.name, container))
 }
 
 function place(d: DesignerDocument, def: ControlDef, x: number, y: number) {
@@ -389,7 +398,15 @@ function place(d: DesignerDocument, def: ControlDef, x: number, y: number) {
   const origin = container ? absRect(d, container) : { x: 0, y: 0 }
   const result = addControl(d, def, container, { x: x - origin.x, y: y - origin.y })
   selected.value = result.name
-  commit(result.doc)
+  commit(def.component ? result.doc : fitInside(result.doc, result.name, container))
+}
+
+/** 新控件比容器宽（LED 显示屏默认 800 宽，新窗体只有 300）：按比例缩小到右边留出边距，不用学生再去改大小 */
+function fitInside(d: DesignerDocument, name: string, container: string): DesignerDocument {
+  const rect = localRect(d, name)
+  const room = (container ? localRect(d, container).width : clientSize.value.width) - rect.x - 12
+  if (rect.width <= room || room < 40) return d
+  return setProp(d, name, 'Size', { kind: 'size', width: room, height: Math.max(20, Math.round((rect.height * room) / rect.width)) })
 }
 
 // ---------- 属性窗口的回调 ----------
@@ -469,6 +486,7 @@ function onComponentDoubleClick(name: string) {
 }
 
 const formTitle = computed(() => String(tree.value?.props.Text ?? ''))
+const borderless = computed(() => tree.value?.props.FormBorderStyle === 'None')
 const formStyle = computed(() => ({
   width: `${clientSize.value.width}px`,
   height: `${clientSize.value.height}px`,
@@ -511,7 +529,9 @@ const noop = () => {}
       <div class="actions">
         <button :disabled="!canUndo" title="撤销（Ctrl+Z）" @click="emit('undo')">↶ 撤销</button>
         <button :disabled="!canRedo" title="重做（Ctrl+Y）" @click="emit('redo')">↷ 重做</button>
-        <span class="tips">拖动工具箱里的控件到窗体上；双击控件生成事件处理方法；Delete 删除</span>
+        <span class="tips" title="拖动工具箱里的控件到窗体上；双击控件生成事件处理方法；Delete 删除"
+          >拖动工具箱里的控件到窗体上；双击控件生成事件处理方法；Delete 删除</span
+        >
         <select
           class="zoom"
           title="窗体显示的大小（不影响窗体的实际大小）"
@@ -524,8 +544,9 @@ const noop = () => {}
         </select>
         <button class="view-code" title="设计器根据窗体上的控件自动生成的代码（Designer.cs）" @click="emit('openDesignerFile')">查看生成的代码</button>
       </div>
-      <div class="window" :class="{ selected: selected === '' }" :style="zoom !== 1 ? { zoom } : undefined">
-        <div class="titlebar" @pointerdown="selected = ''">
+      <div class="window" :class="{ selected: selected === '', borderless }" :style="zoom !== 1 ? { zoom } : undefined">
+        <!-- 无边框窗体和 VS 设计器里一样不画标题栏，点窗体空白处选中窗体 -->
+        <div v-if="!borderless" class="titlebar" @pointerdown="selected = ''">
           <span class="title">{{ displayText(formTitle) }}</span>
           <span class="buttons">─ ☐ ✕</span>
         </div>
@@ -707,6 +728,10 @@ const noop = () => {}
   box-shadow: 0 2px 10px rgb(0 0 0 / 0.15);
 }
 
+.window.borderless {
+  border-color: transparent;
+}
+
 .window.selected {
   outline: 1px dashed #2563eb;
   outline-offset: 2px;
diff --git a/web/src/designer/PropertyGrid.vue b/web/src/designer/PropertyGrid.vue
index 209c998..5865b1f 100644
--- a/web/src/designer/PropertyGrid.vue
+++ b/web/src/designer/PropertyGrid.vue
@@ -7,7 +7,7 @@ import ChartDialog from './ChartDialog.vue'
 import type { DesignerDocument } from './document'
 import { checkName, getEventHandler, getItems, getPropText, typeOf } from './edit'
 import { resourceNameOf } from './resources'
-import { NAMED_COLORS, hexToRgb, parseValue, rgb, type Value } from './values'
+import { COLOR_LABELS, NAMED_COLORS, hexToRgb, parseValue, rgb, type Value } from './values'
 
 const props = defineProps<{
   doc: DesignerDocument
@@ -289,7 +289,7 @@ function renameHandler(event: string, value: string) {
             <i class="swatch" :style="{ background: color(prop)?.css ?? 'transparent' }" />
             <select :value="color(prop)?.name ?? (color(prop) ? 'custom' : '')" @change="setColor(prop, ($event.target as HTMLSelectElement).value)">
               <option value="">（默认）</option>
-              <option v-for="(_, name) in NAMED_COLORS" :key="name" :value="name">{{ name }}</option>
+              <option v-for="(_, name) in NAMED_COLORS" :key="name" :value="name" :title="name">{{ COLOR_LABELS[name] ?? name }}</option>
               <option v-if="color(prop) && !color(prop)!.name" value="custom" disabled>{{ color(prop)!.css }}</option>
             </select>
             <input
diff --git a/web/src/designer/code.test.ts b/web/src/designer/code.test.ts
index 61a05c6..3d88872 100644
--- a/web/src/designer/code.test.ts
+++ b/web/src/designer/code.test.ts
@@ -9,7 +9,7 @@ test('插入事件处理方法：放在类的最后，与上一个方法空一
   const code = await Bun.file(FORM1).text()
   const { code: next, line } = ensureHandler(code, 'Form1', 'Form1_Load', 'EventArgs')
   const lines = next.split('\n')
-  expect(lines.slice(line - 4, line + 1)).toEqual(['', '        private void Form1_Load(object sender, EventArgs e)', '        {', '', '        }'])
+  expect(lines.slice(line - 4, line + 1)).toEqual(['', '        private void Form1_Load(object sender, EventArgs e)', '        {', '            ', '        }'])
   // 方法的 "}" 之后就是类的 "}"
   expect(lines[line + 1]).toBe('    }')
 })
@@ -25,7 +25,7 @@ test('类里还没有成员时不留多余空行', () => {
   const code = 'namespace A\n{\n    public partial class F : Form\n    {\n    }\n}\n'
   const { code: next, line } = ensureHandler(code, 'F', 'F_Load', 'EventArgs')
   expect(next).toBe(
-    'namespace A\n{\n    public partial class F : Form\n    {\n        private void F_Load(object sender, EventArgs e)\n        {\n\n        }\n    }\n}\n',
+    'namespace A\n{\n    public partial class F : Form\n    {\n        private void F_Load(object sender, EventArgs e)\n        {\n            \n        }\n    }\n}\n',
   )
   expect(line).toBe(7)
 })
@@ -33,5 +33,5 @@ test('类里还没有成员时不留多余空行', () => {
 test('字符串和注释里的大括号不影响查找类的结尾', () => {
   const code = 'class F\n{\n    string s = "}{";\n    // }\n    char c = \'}\';\n}\n'
   const { code: next } = ensureHandler(code, 'F', 'F_Load', 'EventArgs')
-  expect(next.endsWith("    char c = '}';\n\n    private void F_Load(object sender, EventArgs e)\n    {\n\n    }\n}\n")).toBe(true)
+  expect(next.endsWith("    char c = '}';\n\n    private void F_Load(object sender, EventArgs e)\n    {\n        \n    }\n}\n")).toBe(true)
 })
diff --git a/web/src/designer/code.ts b/web/src/designer/code.ts
index 4201c54..584d69a 100644
--- a/web/src/designer/code.ts
+++ b/web/src/designer/code.ts
@@ -20,7 +20,9 @@ export function ensureHandler(code: string, className: string, handler: string,
   // 类里已有成员时，与上一个成员之间空一行
   const before = code.slice(0, lineStart)
   const hasMembers = !/\{\s*$/.test(before)
-  const method = [...(hasMembers ? [''] : []), `${indent}private void ${handler}(object sender, ${args} e)`, `${indent}{`, '', `${indent}}`].join(eol)
+  // 方法体的空行带好缩进（和 VS 一样），光标跳过去就在缩进后面，学生的代码不会顶格写
+  const body = `${indent}    `
+  const method = [...(hasMembers ? [''] : []), `${indent}private void ${handler}(object sender, ${args} e)`, `${indent}{`, body, `${indent}}`].join(eol)
   const next = `${before}${method}${eol}${code.slice(lineStart)}`
   return { code: next, line: lineOf(next, before.length) + (hasMembers ? 3 : 2) }
 }
diff --git a/web/src/designer/values.ts b/web/src/designer/values.ts
index 083ebd4..74bd65b 100644
--- a/web/src/designer/values.ts
+++ b/web/src/designer/values.ts
@@ -134,6 +134,30 @@ export const NAMED_COLORS: Record<string, string> = {
   Cyan: '#00ffff',
 }
 
+/** 属性窗口里颜色的中文名，英文名放在悬停提示里 */
+export const COLOR_LABELS: Record<string, string> = {
+  Transparent: '透明',
+  Black: '黑色',
+  White: '白色',
+  Red: '红色',
+  Green: '绿色',
+  Blue: '蓝色',
+  Yellow: '黄色',
+  Orange: '橙色',
+  Gray: '灰色',
+  DimGray: '暗灰色',
+  Silver: '银色',
+  LightGray: '浅灰色',
+  DarkBlue: '深蓝色',
+  SkyBlue: '天蓝色',
+  LightGreen: '浅绿色',
+  Lime: '亮绿色',
+  Purple: '紫色',
+  Brown: '棕色',
+  Pink: '粉红色',
+  Cyan: '青色',
+}
+
 /** 系统颜色（System.Drawing.SystemColors），按 Windows 10 默认主题取值 */
 const SYSTEM_COLORS: Record<string, string> = {
   Control: '#f0f0f0',
diff --git a/web/src/editor/CodeEditor.vue b/web/src/editor/CodeEditor.vue
index 00841ab..474b812 100644
--- a/web/src/editor/CodeEditor.vue
+++ b/web/src/editor/CodeEditor.vue
@@ -124,6 +124,8 @@ onMounted(() => {
     tabSize: 4,
     insertSpaces: true,
     minimap: { enabled: false },
+    // 顶部不固定显示所在的类和方法：点报错跳到文件开头附近的行时，那一行会被它挡住
+    stickyScroll: { enabled: false },
     scrollBeyondLastLine: false,
     renderWhitespace: 'selection',
     unicodeHighlight: { ambiguousCharacters: false },
diff --git a/web/src/editor/monaco.ts b/web/src/editor/monaco.ts
index 6f95597..5b2fa7f 100644
--- a/web/src/editor/monaco.ts
+++ b/web/src/editor/monaco.ts
@@ -1,5 +1,7 @@
 // 按需加载 Monaco（0.57 的模块布局）：编辑器 API + 全部编辑功能（查找、折叠、括号匹配等）+ C# 和 SQL 语法高亮，
 // 不加载其他几十种语言和 JS/TS/CSS 语言服务，体积小很多。
+// 中文界面（查找替换、右键菜单、提示文字）：必须在编辑器模块之前加载，编辑器模块加载时就会取界面文字
+import 'monaco-editor/nls/lang/zh-cn'
 import * as monaco from 'monaco-editor/editor/editor.api'
 import 'monaco-editor/features/register.all'
 import 'monaco-editor/languages/definitions/csharp/register'
diff --git a/web/src/grading/TaskPanel.vue b/web/src/grading/TaskPanel.vue
index be1ab5b..b50a34c 100644
--- a/web/src/grading/TaskPanel.vue
+++ b/web/src/grading/TaskPanel.vue
@@ -77,6 +77,7 @@ const formatTime = (ms: number) => new Date(ms).toLocaleTimeString('zh-CN', { ho
     :show-mask="false"
     :trap-focus="false"
     :block-scroll="false"
+    class="task-drawer"
     @update:show="emit('update:show', $event)"
   >
     <NDrawerContent title="任务" closable>
@@ -117,6 +118,13 @@ const formatTime = (ms: number) => new Date(ms).toLocaleTimeString('zh-CN', { ho
   </NDrawer>
 </template>
 
+<style>
+/* 从顶部工具栏下面开始，不挡住"我的作业""数据库""退出"等链接 */
+.n-drawer.task-drawer {
+  top: 49px;
+}
+</style>
+
 <style scoped>
 .task {
   font-size: 14px;
diff --git a/web/src/pages/DatabasePage.vue b/web/src/pages/DatabasePage.vue
index 87205ab..a4910a9 100644
--- a/web/src/pages/DatabasePage.vue
+++ b/web/src/pages/DatabasePage.vue
@@ -10,7 +10,7 @@ import EditTab from '../database/EditTab.vue'
 import ObjectExplorer, { type ExplorerAction } from '../database/ObjectExplorer.vue'
 import QueryTab from '../database/QueryTab.vue'
 import { execute, loadExplorer, quoteName, type ExplorerDatabase, type ExplorerTable } from '../database/sql'
-import { renderSampleTag, sampleOptions } from '../samples'
+import { lastSample, renderSampleTag, sampleOptions } from '../samples'
 
 type Tab =
   | { key: string; kind: 'query'; title: string; database: string; sql?: string; run?: boolean }
@@ -148,7 +148,8 @@ const restoreBusy = ref(false)
 
 async function openRestore() {
   experiments.value = await api('GET', '/api/db/experiments')
-  restoring.value = experiments.value[0]?.id ?? null
+  // 默认选刚才做的实验
+  restoring.value = experiments.value.find((e) => e.id === lastSample())?.id ?? experiments.value[0]?.id ?? null
 }
 
 async function restore() {
diff --git a/web/src/pages/HelpPage.vue b/web/src/pages/HelpPage.vue
index 1712d13..71bfbfe 100644
--- a/web/src/pages/HelpPage.vue
+++ b/web/src/pages/HelpPage.vue
@@ -28,8 +28,8 @@ import { currentUser } from '../auth'
 
         <h3>2. 自由练习和做作业</h3>
         <ul>
-          <li>登录后进入<b>自由练习</b>：左上角的下拉框选教材上的任务，可以随便改、随便运行。</li>
-          <li>点右上角的<b>我的作业</b>，看老师布置的作业、截止时间和得分；点作业名开始做。</li>
+          <li>登录后先看到<b>我的作业</b>：老师布置的作业、截止时间和得分；点作业名开始做。做实验时随时可以点右上角的<b>我的作业</b>回来。</li>
+          <li>点<b>自由练习</b>：左上角的下拉框选教材上的任务，可以随便改、随便运行；下次打开时回到上次做的任务。</li>
           <li>工具栏的<b>任务</b>：任务目标、控件名、实现步骤和在平台上怎么试，第一次打开一个实验时自动弹出。面板不挡住设计器和代码，可以开着做。</li>
           <li>
             作业的起点有两种：<b>界面已做好</b>（只写事件和代码）、<b>空白工程</b>（从搭界面做起）。控件名照书上的写，自动评分按书上的控件名操作你的程序。
diff --git a/web/src/pages/LoginPage.vue b/web/src/pages/LoginPage.vue
index 0df9f8f..1108a3b 100644
--- a/web/src/pages/LoginPage.vue
+++ b/web/src/pages/LoginPage.vue
@@ -17,8 +17,10 @@ async function submit() {
   busy.value = true
   error.value = ''
   try {
-    await login(username.value.trim(), password.value)
-    const redirect = typeof route.query.redirect === 'string' && route.query.redirect.startsWith('/') ? route.query.redirect : '/'
+    const user = await login(username.value.trim(), password.value)
+    // 学生登录后先看作业列表，老师进实验页
+    const fallback = user.role === 'student' ? '/assignments' : '/'
+    const redirect = typeof route.query.redirect === 'string' && route.query.redirect.startsWith('/') ? route.query.redirect : fallback
     await router.replace(redirect)
   } catch (e) {
     error.value = (e as Error).message
diff --git a/web/src/pages/ReviewPage.vue b/web/src/pages/ReviewPage.vue
index 218a144..ab66ff8 100644
--- a/web/src/pages/ReviewPage.vue
+++ b/web/src/pages/ReviewPage.vue
@@ -15,7 +15,7 @@ import RunArea from '../run/RunArea.vue'
 import { createRunSession } from '../run/session'
 import GradeResultView from '../grading/GradeResultView.vue'
 import { conventionHints } from '@iot/shared'
-import { downloadCsv } from '../teacher/csv'
+import { downloadCsv, textCell } from '../teacher/csv'
 
 interface Row {
   userId: number
@@ -270,7 +270,7 @@ function exportCsv() {
       '评语',
     ],
     ...rows.value.map((r) => [
-      `\t${r.username}`,
+      textCell(r.username),
       r.status ? (r.autoScore ?? '') : '未提交',
       ...a.scoring.manual.map((_, i) => r.review?.scores[i] ?? ''),
       r.status ? (r.autoScore ?? 0) + (r.manualScore ?? 0) : '',
@@ -293,7 +293,8 @@ async function signOut() {
       <strong>{{ assignment?.title }}</strong>
       <span class="muted">{{ assignment?.className }}</span>
       <span class="muted">已提交 {{ rows.filter((r) => r.status).length }} / {{ rows.length }} 人</span>
-      <NButton size="small" @click="adoptAll">全部采纳 AI 建议</NButton>
+      <!-- 没配置 AI 评阅时不会有 AI 建议，不显示这个按钮 -->
+      <NButton v-if="rows.some((r) => r.aiStatus)" size="small" @click="adoptAll">全部采纳 AI 建议</NButton>
       <NButton size="small" @click="exportCsv">导出成绩</NButton>
       <span class="spacer" />
       <span class="user">{{ currentUser?.name }}</span>
diff --git a/web/src/pages/TeacherPage.vue b/web/src/pages/TeacherPage.vue
index ac6b696..18ad199 100644
--- a/web/src/pages/TeacherPage.vue
+++ b/web/src/pages/TeacherPage.vue
@@ -7,7 +7,7 @@ import { api } from '../api'
 import { currentUser, logout } from '../auth'
 import AssignmentsPanel from '../teacher/AssignmentsPanel.vue'
 import GradebookPanel from '../teacher/GradebookPanel.vue'
-import { downloadCsv } from '../teacher/csv'
+import { downloadCsv, textCell } from '../teacher/csv'
 import { decodeCsv, parseCsv, toRoster, type RosterRow } from '../teacher/roster'
 
 interface ClassInfo {
@@ -177,7 +177,7 @@ async function confirmImport() {
 
 function exportRoster() {
   if (!selected.value) return
-  downloadCsv(`${selected.value.name}-名单.csv`, [['用户名', '密码'], ...students.value.map((s) => [`\t${s.username}`, `\t${s.password}`])])
+  downloadCsv(`${selected.value.name}-名单.csv`, [['用户名', '密码'], ...students.value.map((s) => [textCell(s.username), textCell(s.password)])])
 }
 
 function downloadTemplate() {
diff --git a/web/src/pages/WorkbenchPage.vue b/web/src/pages/WorkbenchPage.vue
index 27c3eb9..f2d4c6d 100644
--- a/web/src/pages/WorkbenchPage.vue
+++ b/web/src/pages/WorkbenchPage.vue
@@ -30,7 +30,7 @@ import { createRunSession } from '../run/session'
 import GradeResultView from '../grading/GradeResultView.vue'
 import TaskPanel from '../grading/TaskPanel.vue'
 import { captureForms } from '../grading/screenshots'
-import { renderSampleTag, sampleOptions } from '../samples'
+import { lastSample, rememberSample, renderSampleTag, sampleOptions } from '../samples'
 
 const props = defineProps<{ assignmentId?: string; submissionId?: string }>()
 
@@ -128,8 +128,8 @@ onMounted(async () => {
   }
   const list = await api<{ id: string; title: string }[]>('GET', '/api/samples')
   samples.value = sampleOptions(list)
-  // 网址里带 ?sample=示例编号 时直接打开该示例（便于老师把链接发给学生）
-  const initial = list.find((s) => s.id === route.query.sample) ?? list[0]
+  // 网址里带 ?sample=示例编号 时直接打开该示例（便于老师把链接发给学生），否则打开上次做的实验
+  const initial = list.find((s) => s.id === route.query.sample) ?? list.find((s) => s.id === lastSample()) ?? list[0]
   if (initial) await loadSample(initial.id)
 })
 
@@ -150,6 +150,7 @@ async function openProject(key: string, original: () => Promise<SourceFile[]>, d
 async function loadSample(id: string, discardWork = false) {
   sampleId.value = id
   void router.replace({ query: { sample: id } })
+  rememberSample(id)
   sampleChecks.value = []
   sampleTask.value = null
   void api<string[]>('GET', `/api/samples/${encodeURIComponent(id)}/checks`)
@@ -596,7 +597,7 @@ function run() {
       :before-start="flushSave"
     />
 
-    <main class="workspace" :class="{ designing: activeForm, 'run-collapsed': runCollapsed }">
+    <main class="workspace" :class="{ 'run-collapsed': runCollapsed }">
       <section class="editor">
         <div class="tab-row">
           <NTabs v-model:value="activeTab" type="card" size="small" class="file-tabs">
@@ -698,7 +699,7 @@ function run() {
 }
 
 .sample-select {
-  width: 240px;
+  width: 300px;
 }
 
 .metrics {
@@ -758,16 +759,12 @@ function run() {
   white-space: nowrap;
 }
 
+/* 设计页要放工具箱、窗体和属性窗口，代码页要放得下长代码行，左栏都放宽；切换标签页时布局不跳 */
 .workspace {
   flex: 1;
   display: grid;
-  grid-template-columns: minmax(360px, 2fr) 14px 3fr;
-  min-height: 0;
-}
-
-/* 设计器需要工具箱、窗体和属性窗口，左栏放宽 */
-.workspace.designing {
   grid-template-columns: minmax(0, 3fr) 14px minmax(360px, 2fr);
+  min-height: 0;
 }
 
 .workspace.run-collapsed {
@@ -815,6 +812,11 @@ function run() {
   min-width: 0;
 }
 
+/* 文件多时（项目 8 有十来个）标签换行显示，不藏在看不到滚动条的横向滚动里 */
+.file-tabs :deep(.n-tabs-wrapper) {
+  flex-wrap: wrap;
+}
+
 .new-form {
   display: flex;
   flex-direction: column;
diff --git a/web/src/run/RunArea.vue b/web/src/run/RunArea.vue
index 758fc5c..9e4bd04 100644
--- a/web/src/run/RunArea.vue
+++ b/web/src/run/RunArea.vue
@@ -11,7 +11,9 @@ import MessageBoxDialog from '../winforms/MessageBoxDialog.vue'
 import type { RunSession } from './session'
 
 const props = defineProps<{ session: RunSession }>()
-const emit = defineEmits<{ diagnostic: [file: string, line: number, column: number] }>()
+const emit = defineEmits<{
+  diagnostic: [file: string, line: number, column: number]
+}>()
 
 const state = props.session.state
 provide(RUN_IMAGES, props.session.images)
@@ -26,7 +28,10 @@ const maximized = ref(false)
 const desktop = ref<HTMLElement>()
 const desktopSize = ref({ width: 0, height: 0 })
 const observer = new ResizeObserver(([entry]) => {
-  desktopSize.value = { width: entry.contentRect.width, height: entry.contentRect.height }
+  desktopSize.value = {
+    width: entry.contentRect.width,
+    height: entry.contentRect.height,
+  }
 })
 onMounted(() => observer.observe(desktop.value!))
 onBeforeUnmount(() => observer.disconnect())
@@ -39,7 +44,10 @@ const scale = computed(() => {
   state.forms.forEach((form, index) => {
     const p = form.root.props
     if (p.Visible === false) return
-    const client = (p.ClientSize as SizeValue | undefined) ?? { width: 300, height: 300 }
+    const client = (p.ClientSize as SizeValue | undefined) ?? {
+      width: 300,
+      height: 300,
+    }
     const start = WINDOW_MARGIN + index * WINDOW_STEP
     width = Math.max(width, start + client.width + 2 + WINDOW_MARGIN)
     height = Math.max(height, start + client.height + 2 + (p.FormBorderStyle === 'None' ? 0 : TITLEBAR) + WINDOW_MARGIN)
@@ -58,53 +66,54 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKey))
 
 <template>
   <section class="run-area" :class="{ maximized }">
-    <div ref="desktop" class="desktop">
-      <div class="desktop-canvas" :style="scale < 1 ? { transform: `scale(${scale})`, width: `${100 / scale}%`, height: `${100 / scale}%` } : undefined">
-        <FormWindow
-          v-for="(form, index) in state.forms"
-          :key="form.root.id"
-          :form="form.root"
-          :modal="form.modal"
-          :offset="index"
-          :scale="scale"
-          :act="session.act"
-        />
-      </div>
-      <MessageBoxDialog v-for="box in state.messageBoxes" :key="box.requestId" :box="box" @reply="session.replyMessageBox(box.requestId, $event)" />
-      <div v-if="state.connection === 'lost'" class="desktop-hint lost">与服务器的连接断开了，正在重新连接…</div>
-      <div v-else-if="state.connection === 'restored' && state.forms.length === 0" class="desktop-hint lost">
-        连接已恢复。刚才的程序随连接断开已经结束，请重新运行
-      </div>
-      <div v-else-if="state.forms.length === 0" class="desktop-hint">点击"运行"后，学生程序的窗体会显示在这里</div>
+    <div class="stage">
       <div class="desktop-tools">
-        <span v-if="scale < 1" class="desktop-scale" title='窗体比运行区大，按比例缩小显示；点"放大"可以看得更清楚'> 缩放 {{ Math.round(scale * 100) }}% </span>
+        <span v-if="scale < 1" class="desktop-scale" title='窗体比运行区大，按比例缩小显示；点"放大"可以看得更清楚'>缩放 {{ Math.round(scale * 100) }}%</span>
+        <button
+          v-if="maximized && (state.status === 'compiling' || state.status === 'running')"
+          type="button"
+          title="结束正在运行的程序（Shift+F5）"
+          @click="session.stop()"
+        >
+          ■ 停止
+        </button>
         <button type="button" :title="maximized ? '还原（Esc）' : '运行区占满整个网页'" @click="maximized = !maximized">
           {{ maximized ? '还原' : '放大' }}
         </button>
       </div>
-    </div>
-    <TrainingBoard :board="state.board" :playing="state.playing" @set="session.setBoard" @reset="session.resetBoard" />
-    <div v-if="state.savedImages.length" class="photos">
-      <div class="photos-title">程序保存的图片（{{ state.savedImages.length }}）<span>只在这次运行中保留</span></div>
-      <div class="photos-list">
-        <figure
-          v-for="(photo, i) in state.savedImages"
-          :key="i"
-          :title="`${photo.path}（点击查看大图）`"
-          @click="viewing = { path: photo.path, url: session.images.get(photo.image) ?? '' }"
+      <div ref="desktop" class="desktop">
+        <div
+          class="desktop-canvas"
+          :style="
+            scale < 1
+              ? {
+                  transform: `scale(${scale})`,
+                  width: `${100 / scale}%`,
+                  height: `${100 / scale}%`,
+                }
+              : undefined
+          "
         >
-          <img :src="session.images.get(photo.image)" alt="" />
-          <figcaption>{{ photo.path }}</figcaption>
-        </figure>
+          <FormWindow
+            v-for="(form, index) in state.forms"
+            :key="form.root.id"
+            :form="form.root"
+            :modal="form.modal"
+            :offset="index"
+            :scale="scale"
+            :act="session.act"
+          />
+        </div>
+        <MessageBoxDialog v-for="box in state.messageBoxes" :key="box.requestId" :box="box" @reply="session.replyMessageBox(box.requestId, $event)" />
+        <div v-if="state.connection === 'lost'" class="desktop-hint lost">与服务器的连接断开了，正在重新连接…</div>
+        <div v-else-if="state.connection === 'restored' && state.forms.length === 0" class="desktop-hint lost">
+          连接已恢复。刚才的程序随连接断开已经结束，请重新运行
+        </div>
+        <div v-else-if="state.forms.length === 0" class="desktop-hint">点击"运行"后，学生程序的窗体会显示在这里</div>
       </div>
     </div>
-    <div v-if="viewing" class="photo-viewer" @click="viewing = null">
-      <figure>
-        <img :src="viewing.url" alt="" />
-        <figcaption>{{ viewing.path }}（点击任意处关闭）</figcaption>
-      </figure>
-    </div>
-    <div class="output">
+    <!-- 编译错误、异常、控制台输出和保存的图片紧跟在桌面下面，不会被很高的实训台挤到看不见的地方 -->
+    <div v-if="state.diagnostics.length || state.errors.length || state.console" class="output">
       <div
         v-for="(d, i) in state.diagnostics"
         :key="`d${i}`"
@@ -115,9 +124,41 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKey))
         {{ d.file }}({{ d.line }},{{ d.column }}) {{ d.code }}：{{ d.message }}
         <div v-if="d.hint" class="hint">提示：{{ d.hint }}</div>
       </div>
-      <pre v-for="(e, i) in state.errors" :key="`e${i}`" class="error">{{ e }}</pre>
+      <pre
+        v-for="(e, i) in state.errors"
+        :key="`e${i}`"
+        :class="['error', { jump: e.file && e.line }]"
+        :title="e.file && e.line ? '点击跳到出错的代码' : undefined"
+        @click="e.file && e.line && emit('diagnostic', e.file, e.line, 1)"
+        >{{ e.text }}</pre>
       <pre v-if="state.console" class="console">{{ state.console }}</pre>
     </div>
+    <div v-if="state.savedImages.length" class="photos">
+      <div class="photos-title">程序保存的图片（{{ state.savedImages.length }}）<span>只在这次运行中保留</span></div>
+      <div class="photos-list">
+        <figure
+          v-for="(photo, i) in state.savedImages"
+          :key="i"
+          :title="`${photo.path}（点击查看大图）`"
+          @click="
+            viewing = {
+              path: photo.path,
+              url: session.images.get(photo.image) ?? '',
+            }
+          "
+        >
+          <img :src="session.images.get(photo.image)" alt="" />
+          <figcaption>{{ photo.path }}</figcaption>
+        </figure>
+      </div>
+    </div>
+    <TrainingBoard :board="state.board" :playing="state.playing" @set="session.setBoard" @reset="session.resetBoard" />
+    <div v-if="viewing" class="photo-viewer" @click="viewing = null">
+      <figure>
+        <img :src="viewing.url" alt="" />
+        <figcaption>{{ viewing.path }}（点击任意处关闭）</figcaption>
+      </figure>
+    </div>
   </section>
 </template>
 
@@ -131,6 +172,18 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKey))
   overflow: auto;
 }
 
+/* 运行区内容超出高度时整体滚动，除了桌面都不被压缩 */
+.run-area > :not(.stage) {
+  flex-shrink: 0;
+}
+
+.stage {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+}
+
 .desktop {
   position: relative;
   flex: 1;
@@ -151,36 +204,31 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKey))
   transform-origin: 0 0;
 }
 
+/* 放在桌面上方，不压住学生窗体的标题栏按钮 */
 .desktop-tools {
-  position: absolute;
-  top: 6px;
-  right: 6px;
-  z-index: 100001;
   display: flex;
   align-items: center;
+  justify-content: flex-end;
   gap: 6px;
   font-size: 12px;
 }
 
 .desktop-scale {
-  padding: 2px 6px;
-  border-radius: 3px;
-  background: rgb(0 0 0 / 0.35);
-  color: #fff;
+  color: #6b7280;
 }
 
 .desktop-tools button {
-  padding: 2px 10px;
-  border: 1px solid rgb(255 255 255 / 0.6);
+  padding: 1px 10px;
+  border: 1px solid #d1d5db;
   border-radius: 3px;
-  background: rgb(0 0 0 / 0.35);
-  color: #fff;
+  background: #fff;
+  color: #374151;
   font-size: 12px;
   cursor: pointer;
 }
 
 .desktop-tools button:hover {
-  background: rgb(0 0 0 / 0.55);
+  border-color: #9ca3af;
 }
 
 /* 放大：桌面在左边占满高度，实训台、图片列表和输出在右边一栏 */
@@ -195,13 +243,13 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKey))
   background: #f3f4f6;
 }
 
-.run-area.maximized .desktop {
+.run-area.maximized .stage {
   grid-column: 1;
   grid-row: 1 / span 20;
   height: calc(100vh - 16px);
 }
 
-.run-area.maximized > :not(.desktop) {
+.run-area.maximized > :not(.stage) {
   grid-column: 2;
 }
 
@@ -293,11 +341,19 @@ onBeforeUnmount(() => window.removeEventListener('keydown', onKey))
   font-size: 12px;
 }
 
-.diag {
+/* 长的报错和输出折行显示，不用左右滚动 */
+.output pre {
+  white-space: pre-wrap;
+  word-break: break-all;
+}
+
+.diag,
+.error.jump {
   cursor: pointer;
 }
 
-.diag:hover {
+.diag:hover,
+.error.jump:hover {
   text-decoration: underline;
 }
 
diff --git a/web/src/run/session.ts b/web/src/run/session.ts
index 37f8d2c..7731c07 100644
--- a/web/src/run/session.ts
+++ b/web/src/run/session.ts
@@ -8,6 +8,12 @@ export interface OpenForm {
 }
 
 /** 学生程序保存的图片（如摄像头照片），path 相对程序所在目录 */
+export interface RunError {
+  text: string
+  file?: string
+  line?: number
+}
+
 export interface SavedImage {
   path: string
   image: string
@@ -27,7 +33,8 @@ export function createRunSession() {
     status: 'idle' as 'idle' | 'compiling' | 'running' | 'stopped',
     diagnostics: [] as Diagnostic[],
     console: '',
-    errors: [] as string[],
+    /** 运行出错、连接断开等提示；运行时异常带着出错的文件和行号，点击跳过去 */
+    errors: [] as RunError[],
     forms: [] as OpenForm[],
     messageBoxes: [] as PendingMessageBox[],
     /** 虚拟实训台，由服务器推送；连接建立前为 null */
@@ -103,7 +110,7 @@ export function createRunSession() {
           ws.onclose = () => {
             // 服务器那边的程序随连接一起结束了；窗体留在页面上只会"点了没反应"
             if (!closed && (state.forms.length > 0 || state.status === 'compiling' || state.status === 'running')) {
-              state.errors.push('与服务器的连接断开了（网络不稳或服务器正在更新），程序已经结束。连上之后请重新运行。')
+              state.errors.push({ text: '与服务器的连接断开了（网络不稳或服务器正在更新），程序已经结束。连上之后请重新运行。' })
             }
             stopAudio()
             state.forms = []
@@ -131,7 +138,7 @@ export function createRunSession() {
   async function run(files: SourceFile[], sampleId?: string) {
     await connect()
     if (socket?.readyState !== WebSocket.OPEN) {
-      state.errors = ['连不上服务器，请检查网络，稍后再点"运行"。']
+      state.errors = [{ text: '连不上服务器，请检查网络，稍后再点"运行"。' }]
       return
     }
     state.connection = 'open'
@@ -194,6 +201,12 @@ export function createRunSession() {
     switch (message.type) {
       case 'status':
         state.status = message.state
+        // 点"停止"时服务器直接结束进程，不再发 exited；窗体留着只会"点了没反应"
+        if (message.state === 'stopped') {
+          stopAudio()
+          state.forms = []
+          state.messageBoxes = []
+        }
         break
       case 'compiled':
         state.diagnostics = message.diagnostics
@@ -259,10 +272,10 @@ export function createRunSession() {
         state.console += message.text
         break
       case 'exception':
-        state.errors.push(`${message.message}\n${message.detail}`)
+        state.errors.push({ text: `运行出错：${message.message}\n${message.detail}`, file: message.file, line: message.line })
         break
       case 'serverError':
-        state.errors.push(message.message)
+        state.errors.push({ text: message.message })
         break
       case 'exited':
         stopAudio()
diff --git a/web/src/samples.ts b/web/src/samples.ts
index 7c0f6a9..6e28c19 100644
--- a/web/src/samples.ts
+++ b/web/src/samples.ts
@@ -1,4 +1,4 @@
-// 实验下拉菜单：按教材的项目分组，组名是项目名，组里每项只写"任务N …"；选中后框里显示完整标题
+// 实验下拉菜单：按教材的项目分组，组名是项目名，组里每项只写"任务N …"；选中后框里显示完整标题。另外记住上次做的实验
 import { h } from 'vue'
 import type { SelectGroupOption, SelectOption, SelectRenderTag } from 'naive-ui'
 
@@ -32,3 +32,22 @@ export function sampleOptions(list: { id: string; title: string }[]): SelectGrou
 
 /** 选择框里显示完整标题（带项目号），下拉列表里仍是简短的"任务N …" */
 export const renderSampleTag: SelectRenderTag = ({ option }) => h('span', { title: option.title as string }, option.title as string)
+
+// 记住上次做的实验：从数据库页面返回、重新登录后回到这个实验，恢复数据时默认选它
+const LAST_SAMPLE_KEY = 'iot-sim:last-sample'
+
+export function lastSample() {
+  try {
+    return localStorage.getItem(LAST_SAMPLE_KEY)
+  } catch {
+    return null
+  }
+}
+
+export function rememberSample(id: string) {
+  try {
+    localStorage.setItem(LAST_SAMPLE_KEY, id)
+  } catch {
+    // 浏览器禁用了本地存储：下次打开第一个实验
+  }
+}
diff --git a/web/src/teacher/GradebookPanel.vue b/web/src/teacher/GradebookPanel.vue
index d74741f..3f3cf9d 100644
--- a/web/src/teacher/GradebookPanel.vue
+++ b/web/src/teacher/GradebookPanel.vue
@@ -4,7 +4,7 @@ import { computed, h, ref, watch } from 'vue'
 import { useRouter } from 'vue-router'
 import { NButton, NDataTable, NEmpty, useMessage, type DataTableColumns } from 'naive-ui'
 import { api } from '../api'
-import { downloadCsv } from './csv'
+import { downloadCsv, textCell } from './csv'
 
 interface Cell {
   submitted: boolean
@@ -61,11 +61,14 @@ const columns = computed<DataTableColumns<Row>>(() => [
   { title: `合计（${fullMarks.value}）`, key: 'sum', width: 110, sorter: (a: Row, b: Row) => sum(a) - sum(b), render: (row: Row) => String(sum(row)) },
 ])
 
+/** 有 AI 建议分时才解释"AI 建议，待确认"（没配置 AI 评阅时不会出现） */
+const hasAi = computed(() => book.value.students.some((s) => Object.values(s.scores).some((c) => c.aiManual !== null)))
+
 function exportCsv() {
   downloadCsv(`${props.className}-成绩表.csv`, [
     ['用户名', ...book.value.assignments.map((a) => `${a.title}（${a.total}）`), `合计（${fullMarks.value}）`],
     ...book.value.students.map((s) => [
-      `\t${s.username}`,
+      textCell(s.username),
       ...book.value.assignments.map((a) => (s.scores[a.id]?.submitted ? s.scores[a.id].total : '未交')),
       sum(s),
     ]),
@@ -76,7 +79,10 @@ function exportCsv() {
 <template>
   <div>
     <div class="head">
-      <span class="tip">总分 = 最近一次提交的自动评分 + 老师评分；"AI 建议，待确认"是含 AI 建议分的总分，老师采纳后才算数；"待评"只含自动评分。</span>
+      <span class="tip"
+        >总分 = 最近一次提交的自动评分 + 老师评分；<template v-if="hasAi">"AI 建议，待确认"是含 AI 建议分的总分，老师采纳后才算数；</template
+        >"待评"只含自动评分。</span
+      >
       <NButton size="small" :disabled="book.students.length === 0" @click="exportCsv">导出成绩表（CSV）</NButton>
     </div>
     <NDataTable
diff --git a/web/src/teacher/csv.ts b/web/src/teacher/csv.ts
index 93f849d..0c6ae91 100644
--- a/web/src/teacher/csv.ts
+++ b/web/src/teacher/csv.ts
@@ -1,5 +1,5 @@
 // 下载 CSV：开头带 BOM，Excel 打开时中文不乱码。
-// 账号、密码等长数字前加制表符（cell 以 \t 开头），Excel 不会把它变成科学计数法。
+// 账号、密码这类纯数字的文字用 textCell 包一下，Excel 不会把它变成数字（丢掉开头的 0、变成科学计数法）。
 export function downloadCsv(filename: string, rows: (string | number | null)[][]) {
   const quote = (value: string | number | null) => {
     const cell = value === null ? '' : String(value)
@@ -12,3 +12,6 @@ export function downloadCsv(filename: string, rows: (string | number | null)[][]
   link.click()
   URL.revokeObjectURL(link.href)
 }
+
+/** 纯数字时前面加制表符，Excel 按文字处理；姓名等其他文字原样输出，不留多余的空白 */
+export const textCell = (value: string) => (/^\d+$/.test(value) ? `\t${value}` : value)
diff --git a/web/src/winforms/ControlView.vue b/web/src/winforms/ControlView.vue
index b6d70f3..a354ef7 100644
--- a/web/src/winforms/ControlView.vue
+++ b/web/src/winforms/ControlView.vue
@@ -1,7 +1,7 @@
 <script setup lang="ts">
 // 按控件类型渲染一个 WinForms 控件及其子控件。
 // 用户操作只通过 act() 上报，由运行器按真实 WinForms 的顺序触发事件。
-import { computed, inject, provide, ref, type CSSProperties } from 'vue'
+import { computed, inject, onBeforeUnmount, provide, ref, watch, type CSSProperties } from 'vue'
 import type { ControlNode, UserAction } from '@iot/shared'
 import { AMBIENT_BACK_COLOR, AMBIENT_BACK_TYPES, boxCss, DEFAULT_BACK_COLOR, displayText } from './format'
 import { backgroundCss, imageSources, RUN_IMAGES, srcset, type ImageValue } from './images'
@@ -49,10 +49,12 @@ const passwordChar = computed(() => {
   return ch && ch !== '\0' ? ch : ''
 })
 
-// ComboBox
+// ComboBox：下拉列表挂到页面最外层（和真实 WinForms 一样可以伸出窗体），按控件在屏幕上的位置和缩放摆放
 const dropDownOpen = ref(false)
 const items = computed(() => (p.value.Items as string[] | undefined) ?? [])
 const editable = computed(() => p.value.DropDownStyle !== 'DropDownList')
+const combo = ref<HTMLElement>()
+const listStyle = ref<CSSProperties>({})
 
 function openDropDown() {
   if (!enabled.value) return
@@ -60,11 +62,37 @@ function openDropDown() {
     dropDownOpen.value = false
     return
   }
+  const el = combo.value
+  if (!el) return
+  const rect = el.getBoundingClientRect()
+  listStyle.value = {
+    left: `${rect.left}px`,
+    top: `${rect.bottom}px`,
+    width: `${el.offsetWidth}px`,
+    transform: `scale(${rect.width / el.offsetWidth || 1})`,
+    font: getComputedStyle(el).font,
+  }
   // 先触发 Click（教材在 Click 里填充串口列表），列表随后按最新的 Items 显示
   act({ action: 'dropDown' })
   dropDownOpen.value = true
 }
 
+/** 点列表以外的地方、滚动页面时收起列表 */
+function closeOnOutside(event: Event) {
+  const target = event.target as Node
+  if (combo.value?.contains(target) || (target instanceof Element && target.closest('.wf-combobox-list'))) return
+  dropDownOpen.value = false
+}
+watch(dropDownOpen, (open) => {
+  const method = open ? 'addEventListener' : 'removeEventListener'
+  window[method]('mousedown', closeOnOutside, true)
+  window[method]('scroll', closeOnOutside, true)
+})
+onBeforeUnmount(() => {
+  window.removeEventListener('mousedown', closeOnOutside, true)
+  window.removeEventListener('scroll', closeOnOutside, true)
+})
+
 function selectItem(index: number) {
   dropDownOpen.value = false
   act({ action: 'select', index })
@@ -130,7 +158,7 @@ const itemHeight = computed(() => `${(p.value.ItemHeight as number | undefined)
   </div>
 
   <!-- ComboBox -->
-  <div v-else-if="node.type === 'ComboBox'" class="wf-control wf-combobox" :style="style">
+  <div v-else-if="node.type === 'ComboBox'" ref="combo" class="wf-control wf-combobox" :style="style">
     <input
       :value="String(p.Text ?? '')"
       :readonly="!editable"
@@ -139,10 +167,12 @@ const itemHeight = computed(() => `${(p.value.ItemHeight as number | undefined)
       @input="act({ action: 'text', value: ($event.target as HTMLInputElement).value })"
     />
     <span class="wf-combobox-arrow" @mousedown.prevent="openDropDown">▾</span>
-    <ul v-if="dropDownOpen" class="wf-combobox-list">
-      <li v-for="(item, index) in items" :key="index" @mousedown.prevent="selectItem(index)">{{ item }}</li>
-      <li v-if="items.length === 0" class="wf-combobox-empty">&nbsp;</li>
-    </ul>
+    <Teleport to="body">
+      <ul v-if="dropDownOpen" class="wf-combobox-list" :style="listStyle">
+        <li v-for="(item, index) in items" :key="index" @mousedown.prevent="selectItem(index)">{{ item }}</li>
+        <li v-if="items.length === 0" class="wf-combobox-empty">&nbsp;</li>
+      </ul>
+    </Teleport>
   </div>
 
   <!-- ListBox：点空白处只触发 Click，点某一项先选中再触发 Click -->
diff --git a/web/src/winforms/winforms.css b/web/src/winforms/winforms.css
index 6810631..008e5cc 100644
--- a/web/src/winforms/winforms.css
+++ b/web/src/winforms/winforms.css
@@ -136,12 +136,12 @@
   background: #fff;
 }
 
+/* 挂在 body 下，位置、宽度、缩放和字体由 ControlView.vue 按下拉框算好 */
 .wf-combobox-list {
-  position: absolute;
-  top: 100%;
-  left: 0;
-  right: 0;
-  z-index: 5;
+  position: fixed;
+  z-index: 2000;
+  box-sizing: border-box;
+  transform-origin: 0 0;
   margin: 0;
   padding: 0;
   list-style: none;