项目 5 补齐：旧版线程 API（Suspend / Resume / Abort）与 ListBox

- 编译时把 Thread 的 Suspend / Resume / Abort、ThreadState、Sleep、new Thread 改写成平台的协作式实现：被挂起或终止的线程在 Sleep、后台改控件、调设备类库、弹提示框时停下或结束； ThreadStateException 等行为与 .NET Framework 一致；编辑器不再提示"已过时" - ListBox：列表项、单选、SelectedIndexChanged 先于 Click、删除选中项后取消选中； ComboBox 与 ListBox 共用 ListControl 和列表项集合；设计器工具箱加"列表框" - 评分规则的"包含"对列表框检查所有列表项 - 示例：项目 5 任务 2（烟雾，线程）、任务 3（推送灾情，二维数组、两个窗体、ListBox），参考答案修正书上直接 Abort 挂起线程、烟雾记成"发现火情"的问题 - 一直不换行的 Console 输出攒满 4096 字符先发出，避免占满内存 - 测试：旧版线程 API、ListBox 事件顺序、两个示例的端到端和评分测试 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-22 20:33:12 +08:00
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commit 91b39603a2
@@ -0,0 +1,165 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Threading;
+
+namespace Sim.Host;
+
+/// <summary>
+/// 教材项目 5 用到的旧版线程 API：Thread.Suspend / Resume / Abort 在新版 .NET 上会抛出 PlatformNotSupportedException。
+/// 编译时把学生代码里对它们（以及 new Thread、Thread.Sleep、ThreadState）的调用改写成这里的方法（见 Sim.Runner/LegacyThreadRewriter.cs）。
+/// <para>
+/// 新版 .NET 不能从外部强行停住或中止一个线程，所以这里是"协作式"的：被挂起或中止的线程在下一个检查点停下或结束。
+/// 检查点是 Thread.Sleep、从后台线程修改控件属性、调用设备类库、弹出提示框，
+/// 教材里的线程方法每次循环都会经过它们，看到的效果和 .NET Framework 一致。
+/// </para>
+/// </summary>
+[EditorBrowsable(EditorBrowsableState.Never)]
+public static class LegacyThreads
+{
+    private sealed class State
+    {
+        public volatile bool Suspended;
+        public volatile bool AbortRequested;
+    }
+
+    // 线程少、操作不频繁，用一把锁保护所有线程的状态；挂起和休眠都在这把锁上等待
+    private static readonly object Gate = new();
+    private static readonly ConditionalWeakTable<Thread, State> States = new();
+
+    /// <summary>当前线程是学生用 new Thread 创建的线程时，指向它的状态</summary>
+    [ThreadStatic] private static State? _current;
+
+    private static State StateOf(Thread thread) => States.GetValue(thread, static _ => new State());
+
+    // ---------- 改写后的调用 ----------
+
+    /// <summary>new Thread(GetData) → new Thread(Wrap(new ThreadStart(GetData)))：线程被中止时安静地结束</summary>
+    public static ThreadStart Wrap(ThreadStart start) => () => RunThread(() => start());
+
+    public static ParameterizedThreadStart Wrap(ParameterizedThreadStart start) => obj => RunThread(() => start(obj));
+
+    private static void RunThread(Action body)
+    {
+        var state = StateOf(Thread.CurrentThread);
+        _current = state;
+        try
+        {
+            // 启动前就被 Abort 的线程（.NET Framework 里启动后立即结束）
+            CheckPoint(state);
+            body();
+        }
+        catch (ThreadAbortedException)
+        {
+            // 和 .NET Framework 一样，被中止的线程结束时不算未处理的异常
+        }
+    }
+
+    public static void Suspend(Thread thread)
+    {
+        lock (Gate)
+        {
+            if ((thread.ThreadState & (ThreadState.Unstarted | ThreadState.Stopped)) != 0)
+                throw new ThreadStateException("线程没有在运行，无法挂起。");
+            StateOf(thread).Suspended = true;
+        }
+        // 线程挂起自己：立即停下，直到别的线程调用 Resume
+        if (thread == Thread.CurrentThread) CheckPoint(StateOf(thread));
+    }
+
+    public static void Resume(Thread thread)
+    {
+        lock (Gate)
+        {
+            var state = StateOf(thread);
+            if (!state.Suspended) throw new ThreadStateException("线程没有被挂起，无法继续（Resume 只能用在调用过 Suspend 的线程上）。");
+            state.Suspended = false;
+            Monitor.PulseAll(Gate);
+        }
+    }
+
+    public static void Abort(Thread thread) => Abort(thread, null);
+
+    public static void Abort(Thread thread, object? stateInfo)
+    {
+        lock (Gate)
+        {
+            if ((thread.ThreadState & ThreadState.Stopped) != 0) return;
+            var state = StateOf(thread);
+            state.AbortRequested = true;
+            // 正在 Thread.Sleep 的线程立即醒来结束
+            Monitor.PulseAll(Gate);
+            // .NET Framework 不能直接中止挂起的线程：抛出异常，等它被 Resume 后才结束
+            if (state.Suspended) throw new ThreadStateException("线程已挂起，不能直接终止。先调用 Resume() 让线程继续，再调用 Abort()。");
+        }
+        if (thread == Thread.CurrentThread) throw new ThreadAbortedException();
+    }
+
+    /// <summary>thd.ThreadState：在真实状态上加上挂起、请求中止</summary>
+    public static ThreadState GetThreadState(Thread thread)
+    {
+        var actual = thread.ThreadState;
+        if (!States.TryGetValue(thread, out var state) || (actual & ThreadState.Stopped) != 0) return actual;
+        var result = actual & (ThreadState.Background | ThreadState.Unstarted);
+        if (state.Suspended) result |= ThreadState.Suspended;
+        else if ((actual & ThreadState.Unstarted) == 0) result |= actual & ThreadState.WaitSleepJoin;
+        if (state.AbortRequested) result |= ThreadState.AbortRequested;
+        return result;
+    }
+
+    public static void Sleep(int millisecondsTimeout)
+    {
+        var state = _current;
+        if (state == null)
+        {
+            Thread.Sleep(millisecondsTimeout);
+            return;
+        }
+        if (millisecondsTimeout < Timeout.Infinite) throw new ArgumentOutOfRangeException(nameof(millisecondsTimeout), "休眠时间不能是负数（-1 表示一直休眠）。");
+        CheckPoint(state);
+        var deadline = Environment.TickCount64 + millisecondsTimeout;
+        lock (Gate)
+        {
+            // 休眠中被 Abort 时提前醒来；被 Suspend 的线程睡完后在检查点停下
+            while (!state.AbortRequested)
+            {
+                if (millisecondsTimeout == Timeout.Infinite)
+                {
+                    Monitor.Wait(Gate);
+                    continue;
+                }
+                var remaining = deadline - Environment.TickCount64;
+                if (remaining <= 0) break;
+                Monitor.Wait(Gate, (int)remaining);
+            }
+        }
+        CheckPoint(state);
+    }
+
+    public static void Sleep(TimeSpan timeout) => Sleep((int)timeout.TotalMilliseconds);
+
+    // ---------- 检查点 ----------
+
+    /// <summary>平台内部使用：学生创建的线程在这里响应 Suspend 和 Abort（其他线程直接返回）</summary>
+    public static void CheckPoint()
+    {
+        var state = _current;
+        if (state != null) CheckPoint(state);
+    }
+
+    private static void CheckPoint(State state)
+    {
+        if (!state.Suspended && !state.AbortRequested) return;
+        lock (Gate)
+        {
+            while (state.Suspended) Monitor.Wait(Gate);
+            if (state.AbortRequested) throw new ThreadAbortedException();
+        }
+    }
+}
+
+/// <summary>线程被 Abort 时在线程里抛出（对应 .NET Framework 的 ThreadAbortException）</summary>
+public sealed class ThreadAbortedException : Exception
+{
+    public ThreadAbortedException() : base("正在中止线程。") { }
+}
@@ -77,13 +77,17 @@ public static class SimHost

    public static void SendConsole(string text) => Send(new JsonObject { ["type"] = "console", ["text"] = text });

-    public static void SendDevice(string device, string action, object? data) => Send(new JsonObject
+    public static void SendDevice(string device, string action, object? data)
    {
-        ["type"] = "device",
-        ["device"] = device,
-        ["action"] = action,
-        ["data"] = PropValue.From(data),
-    });
+        LegacyThreads.CheckPoint();
+        Send(new JsonObject
+        {
+            ["type"] = "device",
+            ["device"] = device,
+            ["action"] = action,
+            ["data"] = PropValue.From(data),
+        });
+    }

    // ---------- 异常 ----------

@@ -121,6 +125,7 @@ public static class SimHost
    /// </summary>
    public static JsonNode? Request(JsonObject message)
    {
+        LegacyThreads.CheckPoint();
        var id = Interlocked.Increment(ref _nextRequestId);
        var pending = new PendingRequest();
        Requests[id] = pending;