整理教材示例：项目 1 任务 2、项目 4 任务 1 和 3、项目 5 任务 1

- 界面取自配套参考工程，用设计器引擎按书上表格改控件名（label1 → lbl_port 等），
  去掉 BOM、换行统一为 LF；代码按书整理，修正 boolIsOpen 等印刷错误
- 测试：所有示例都能编译（10 个），以及计算器 / 多态、红外对射、报警灯、火焰的行为测试

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

samples/p4-t3-报警灯/Form1.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.IO.Ports;
+using DeviceCtrlLibrary;
+
+namespace 报警灯
+{
+    public partial class Form1 : Form
+    {
+        public Form1()
+        {
+            InitializeComponent();
+        }
+
+        bool IsOpen = false;
+
+        private void Form1_Load(object sender, EventArgs e)
+        {
+            com_port.Items.Clear();
+            foreach (string item in SerialPort.GetPortNames())
+            {
+                com_port.Items.Add(item);
+            }
+        }
+
+        private void AlarmOnOff(string Device, bool IsOpen)
+        {
+            //利用switch语句打开或关闭继电器模块
+            switch (Device)
+            {
+                case "Alarm":
+                    DeviceCtrlHelper.adam4150Helper.OnOff(0, IsOpen);//报警灯接入DO0
+                    alarm1.OnOff(IsOpen);//更改界面报警灯状态
+                    break;
+                case "LED1": DeviceCtrlHelper.adam4150Helper.OnOff(1, IsOpen); break;//开启或关闭继电器1模块
+                case "LED2": DeviceCtrlHelper.adam4150Helper.OnOff(2, IsOpen); break;//开启或关闭继电器2模块
+                default: MessageBox.Show("没有合适的接口程序！", "错误提示！"); break;//若为其他模块，则提示错误
+            }
+        }
+
+        private void btn_open_Click(object sender, EventArgs e)
+        {
+            IsOpen = !IsOpen;
+            if (IsOpen)
+            {
+                DeviceCtrlHelper.adam4150Helper.Open(com_port.Text);
+                btn_open.Text = "关闭";
+            }
+            else
+            {
+                DeviceCtrlHelper.adam4150Helper.Close();
+                btn_open.Text = "开启";
+            }
+        }
+
+        private void btn_alarmOpen_Click(object sender, EventArgs e)
+        {
+            AlarmOnOff("Alarm", true);
+        }
+
+        private void btn_alarmClose_Click(object sender, EventArgs e)
+        {
+            AlarmOnOff("Alarm", false);
+        }
+    }
+}