Cad 反应器 cad c#二次开发

        在 AutoCAD C# 二次开发中，`DocumentCollectionEventHandler` 是一个委托（delegate），用于处理与 AutoCAD 文档集合（DocumentCollection）相关的事件。它属于 AutoCAD .NET API 的事件处理机制，本质上是一种**反应器（Reactor）模式**的实现，用于响应文档生命周期事件（如创建、激活、销毁文档等）。

 本例为每激活一个文档，当前文档画一个圆。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
[assembly:CommandClass(typeof(IfoxDemo.DEMO))]namespace IfoxDemo
{public class DEMO{[CommandMethod("xx")]public void CreatExcel(){Document doc = Application.DocumentManager.MdiActiveDocument;Editor ed = doc.Editor;ed.WriteMessage("\n开始批量提取块属性");}}public class DocumentEventReactor{public DocumentEventReactor()// 初始化时订阅事件{DocumentCollection docCol = Application.DocumentManager;docCol.DocumentActivated += OnDocumentActivated;}// 订阅事件（仅允许调用一次）public void Subscribe(){DocumentCollection docCol = Application.DocumentManager;docCol.DocumentActivated -= OnDocumentActivated; // 避免重复订阅docCol.DocumentActivated += OnDocumentActivated;}public void Unsubscribe() // 清理时取消订阅（重要！）{DocumentCollection docCol = Application.DocumentManager;docCol.DocumentActivated -= OnDocumentActivated;}// 文档激活事件处理public void OnDocumentActivated(object sender, DocumentCollectionEventArgs e){Document activeDoc = e.Document;Editor ed = activeDoc.Editor;Database db = activeDoc.Database;// 获取文档名称（不含路径）string docName = System.IO.Path.GetFileName(activeDoc.Name);// 在命令行显示提示ed.WriteMessage($"\n切换到文档: {docName} | 事件类型: {e.GetType().Name}");// 示例扩展操作：检查文档是否只读if (activeDoc.IsReadOnly) ed.WriteMessage("\n警告：当前文档为只读模式！");//// 锁定文档上下文（确保操作在正确文档中执行）using (DocumentLock docLock = activeDoc.LockDocument()){Circle c = new Circle(new Point3d(0, 0, 0), Vector3d.ZAxis, 5.0);c.ColorIndex = 1; // 设置颜色索引Application.DocumentManager.MdiActiveDocument.Database.AddEntityToModeSpace(c); // 添加圆到模型空间Application.DocumentManager.MdiActiveDocument.Editor.ZoomExtents(); // 缩放到适合视图  }}}// 在插件入口初始化//public class PluginCommands : IExtensionApplication//{//    private static DocumentEventReactor _reactor;//    public void Initialize()//    {//        _reactor = new DocumentEventReactor();//        Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage(//          "\n文档事件反应器已启动");//    }//    public void Terminate()//    {//        _reactor?.Unsubscribe();//    }//}
}

他常用事件处理示例：

 响应文档创建事件

Application.DocumentManager.DocumentCreated += (sender, e) => 

{

    Editor ed = e.Document.Editor;

    ed.WriteMessage($"\n新文档已创建: {e.Document.Name}");

};

```

#### 响应文档关闭事件

```csharp

Application.DocumentManager.DocumentToBeDestroyed += (sender, e) => 

{

    // 保存自定义数据到外部文件

    string backupPath = $"C:\\Backups\\{e.Document.Name}.settings";

    SaveCustomData(e.Document, backupPath);

};

```

通过合理利用 `DocumentCollectionEventHandler`，您可以构建响应 AutoCAD 文档环境变化的智能插件，显著提升用户体验和自动化水平。

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
[assembly:CommandClass(typeof(IfoxDemo.DEMO))]namespace IfoxDemo
{public class DEMO{[CommandMethod("xx")]public void CreatExcel(){Document doc = Application.DocumentManager.MdiActiveDocument;Editor ed = doc.Editor;ed.WriteMessage("\n开始批量提取块属性");}}public  class DocumentEventReactor{public static void DocumentEventReactor1()// 初始化时订阅事件{DocumentCollection docCol = Application.DocumentManager;docCol.DocumentActivated += OnDocumentActivated;// 也可以订阅其他事件，如 DocumentCreated、DocumentToBeDestroyed 等docCol.DocumentToBeDeactivated += onDocumentToBeDeactivated; // 这里为了示例使用同一处理方法，实际可分开处理不同事件docCol.DocumentToBeDestroyed += onDocumentToBeDeactivated; // 这里为了示例使用同一处理方法，实际可分开处理不同事件}// 订阅事件（仅允许调用一次）public static void Subscribe(){DocumentCollection docCol = Application.DocumentManager;docCol.DocumentActivated -= OnDocumentActivated; // 避免重复订阅docCol.DocumentActivated += OnDocumentActivated;}public static void Unsubscribe() // 清理时取消订阅（重要！）{DocumentCollection docCol = Application.DocumentManager;docCol.DocumentActivated -= OnDocumentActivated;}// 文档激活事件处理public static void OnDocumentActivated(object sender, DocumentCollectionEventArgs e){try{DocumentCollection dc = sender as DocumentCollection;// if (dc == null) return; // 确保 sender 是 DocumentCollection// 先取消旧订阅，避免重复dc.MdiActiveDocument.ImpliedSelectionChanged -= Doc_ImpliedSelectionChanged;dc.MdiActiveDocument.ImpliedSelectionChanged += Doc_ImpliedSelectionChanged; // 订阅 ImpliedSelectionChanged 事件}catch (Exception){throw;}Document activeDoc = e.Document;Editor ed = activeDoc.Editor;Database db = activeDoc.Database;// 获取文档名称（不含路径）string docName = System.IO.Path.GetFileName(activeDoc.Name);// 在命令行显示提示ed.WriteMessage($"\n切换到文档: {docName} | 事件类型: {e.GetType().Name}");// 示例扩展操作：检查文档是否只读if (activeDoc.IsReadOnly) ed.WriteMessage("\n警告：当前文档为只读模式！");//// 锁定文档上下文（确保操作在正确文档中执行）using (DocumentLock docLock = activeDoc.LockDocument()){Circle c = new Circle(new Point3d(0, 0, 0), Vector3d.ZAxis, 5.0);c.ColorIndex = 1; // 设置颜色索引Application.DocumentManager.MdiActiveDocument.Database.AddEntityToModeSpace(c); // 添加圆到模型空间// Application.DocumentManager.MdiActiveDocument.Editor.ZoomExtents(); // 缩放到适合视图  }}public static void onDocumentToBeDeactivated(object sender, DocumentCollectionEventArgs e){try{DocumentCollection dc = sender as DocumentCollection;// if (dc == null) return; // 确保 sender 是 DocumentCollectiondc.MdiActiveDocument.ImpliedSelectionChanged -= Doc_ImpliedSelectionChanged; // 订阅 ImpliedSelectionChanged 事件}catch (Exception){throw;}}// 文档隐含选择集变化事件处理public static void Doc_ImpliedSelectionChanged(object sender, EventArgs e){   Document doc = Application.DocumentManager.MdiActiveDocument; using (DocumentLock dl = doc.LockDocument()){Editor ed = doc.Editor;ed.WriteMessage("\nImpliedSelectionChanged 事件触发！");// 获取当前选择集var psr = ed.SelectImplied();if (psr.Status != PromptStatus.OK) return;// 开启事务using (Transaction tr = doc.TransactionManager.StartTransaction()){try{// 遍历选择集中的实体foreach (ObjectId id in psr.Value.GetObjectIds()){// 通过事务获取实体（需指定OpenMode）Entity ent = tr.GetObject(id, OpenMode.ForRead) as Entity;if (ent != null){// 在命令行显示实体类型和IDed.WriteMessage($"\n实体类型: {ent.GetType().Name}, ID: {id}");// 此处若需要修改实体，需将OpenMode设为ForWrite并在事务中提交}}// 事务完成后提交（只读操作可省略，但建议显式调用以明确意图）tr.Commit();}catch (Exception ex){ed.WriteMessage($"\n事务处理错误: {ex.Message}");tr.Abort(); // 异常时回滚事务}//try//{//    // 1. 创建空的选择集//    SelectionSet emptySelection = null;//    // 2. 使用SetImpliedSelection设置空选择集，清空当前选择//    ed.SetImpliedSelection(emptySelection);//    ed.WriteMessage("\n当前选择集已清空！");//}//catch (Exception ex)//{//    ed.WriteMessage($"\n清空选择集失败: {ex.Message}");//}}}}}public class MyPlugin2 : IExtensionApplication{public void Initialize(){string str = "";//"输入命令\"ywxl\"执行 \n";Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage($"\n插件已加载!(CAD插件定制:山水qq443440204)\n{str}\n");DocumentEventReactor.Subscribe(); // 订阅事件（仅一次）Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("\n文档事件反应器已启动");}public void Terminate(){//Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("\n结束");DocumentEventReactor.Unsubscribe();}}
}