转自：Cad人生

链接：http://www.cnblogs.com/cadlife/p/3463337.html

题目：双击CAD对象，显示自定义对话框实现方法

内容粘贴如下：

 主要是绑定两个事件：一个是 Application.DocumentManager.DocumentLockModeChanged -----  该事件为文档锁定事件，一直在被监测中                   一个是 Application.BeginDoubleClick                        -----  该事件为应用程序的双击事件

 1     class TlsApplication : IExtensionApplication //程序初始化，在加载dll时，cad会自动捕捉并运行该过程

  3     {
  5         void IExtensionApplication.Initialize()
  7         {
  9             TTest.Start();
 11         }
 13         void IExtensionApplication.Terminate()
 15         {
 17         }
 19     }
 20
 21     class TTest
 23     {
 25         static bool m_Veto = false;
 27         public static void Start()
 29         {
 31             Application.DocumentManager.DocumentLockModeChanged += new DocumentLockModeChangedEventHandler(vetoCommand);
 33             Application.BeginDoubleClick += new BeginDoubleClickEventHandler(beginDoubleClick);
 35         }
 37         static void beginDoubleClick(object sender, BeginDoubleClickEventArgs e)
 39         {
 41             Document doc = Application.DocumentManager.MdiActiveDocument;
 43             Editor ed = doc.Editor;
 45             PromptSelectionResult res = ed.SelectImplied();
 47             SelectionSet ss = res.Value;
 49             if (ss != null)
 51             {
 53                 if (ss.Count == 1)
 55                 {
 57                     using (Transaction tr = doc.TransactionManager.StartTransaction())
 59                     {
 61                         Line line = tr.GetObject(ss[0].ObjectId, OpenMode.ForRead) as Line;
 63                         if (line != null)
 65                         {
 67                             ResultBuffer rb = line.GetXDataForApplication("MyApp"); //提取对象的扩展数据
 69                             if (rb != null)
 71                             {
 73                                 m_Veto = true;
 75                             }
 77                         }
 79                     }
 81                 }
 83             }
 85         }
 86
 87         static void vetoCommand(object sender, DocumentLockModeChangedEventArgs e)
 89         {
 91             if (e.GlobalCommandName.ToLower() == "properties") //判断是否是调用属性对话框
 93             {
 95                 if (m_Veto)
 97                 {
 99                     e.Veto();
103                     Application.ShowAlertDialog("hello"); //在此处可以添加自定义对话框
105                     m_Veto = false;
107                 }
109             }
111         }
113     }

原文地址：https://www.cnblogs.com/whlkx/p/8678779.html