转：实体ToolTip显示XData

首先要说明，实现方式不是我的原创，其中ToolTip的实现转自这里，然后XData的设置和获取来自Kean的博客，当然我自己也做了点研究，在这里，然后把这两个技术结合起来就是你将要看到的东西。

先上效果吧。

下面是实现的代码：

public class Class1:IExtensionApplication     {         void IExtensionApplication.Initialize()         {             Mytooltip();         }         void IExtensionApplication.Terminate()         {         }         public void Mytooltip()         {             Document doc =Application.DocumentManager.MdiActiveDocument;             Editor ed = doc.Editor;             ed.PointMonitor += newPointMonitorEventHandler(MytooltipOn);         }         private void MytooltipOn(object sender,PointMonitorEventArgs e)         {             Database db =Application.DocumentManager.MdiActiveDocument.Database;             FullSubentityPath[] ePaths = e.Context.GetPickedEntities();             if (ePaths.Length > 0)             {                 FullSubentityPath ePath = ePaths[0];                 using (Transaction trans = db.TransactionManager.StartTransaction())                 {                     ObjectId entId = ePath.GetObjectIds()[0];                     Entity ent = (Entity)trans.GetObject(entId,OpenMode.ForRead);                     e.AppendToolTipText(GetXData(ent));                     trans.Commit();                 }             }             else             {                 e.AppendToolTipText("\n未指向实体");             }         }         static public string GetXData(Entity ent)         {             string ret = "";             Document doc =Application.DocumentManager.MdiActiveDocument;             Editor ed = doc.Editor;             ResultBuffer rb = ent.XData;             if (rb == null)                 return "该实体不包含XData.";             else             {                 int n = 0;                 foreach (TypedValue tv in rb)                 {                     ret += string.Format("类型值{0} - 类型: {1},值: {2}\n", n, tv.TypeCode, tv.Value);                     n++;                 }                 rb.Dispose();                 return ret;             }         }         [CommandMethod("SetXD")]         static public void SetXData()         {             Document doc =Application.DocumentManager.MdiActiveDocument;             Editor ed = doc.Editor;             PromptEntityOptions peo = newPromptEntityOptions("\n请选择实体：");             PromptEntityResult per = ed.GetEntity(peo);             if (per.Status == PromptStatus.OK)             {                 Transaction trans = doc.TransactionManager.StartTransaction();                 DBObject obj = trans.GetObject(per.ObjectId,OpenMode.ForWrite);                 AddRegAppTableRecord("Test");                 ResultBuffer rb = new ResultBuffer();                 rb.Add(new TypedValue(1001, "Test"));                 rb.Add(new TypedValue(1000, "Greeting! I am the XData"));                 rb.Add(new TypedValue(1000, "Today is very Cold"));                 obj.XData = rb;                 rb.Dispose();                 trans.Commit();                 trans.Dispose();             }         }         static void AddRegAppTableRecord(string regAppName)         {             Document doc =Application.DocumentManager.MdiActiveDocument;             Editor ed = doc.Editor;             Database db = doc.Database;             Transaction trans = doc.TransactionManager.StartTransaction();             RegAppTable rat = (RegAppTable)trans.GetObject(db.RegAppTableId,OpenMode.ForRead, false);             if (!rat.Has(regAppName))             {                 rat.UpgradeOpen();                 RegAppTableRecord ratr = newRegAppTableRecord();                 ratr.Name = regAppName;                 rat.Add(ratr);                 trans.AddNewlyCreatedDBObject(ratr, true);             }             trans.Commit();             trans.Dispose();         }     }

命令SetXD用于设置XData，不然新建的实体是不包含XData的。指向一个实体后，将会自动显示该实体的XData

原文地址：http://blog.csdn.net/gisoracle/article/details/7276782