AutoCAD.Net圆弧半径标注延长线

本帖转载于：AutoCAD.Net圆弧半径标注延长线 - 程序园 (voidcn.com)（略有改动）

#region 注册RegApp
public static void CheckRegApp(string regapptablename)
{
    Database db = HostApplicationServices.WorkingDatabase;
    using (Transaction trans = db.TransactionManager.StartTransaction())
    {
        RegAppTable appTbl = trans.GetObject(db.RegAppTableId, OpenMode.ForWrite) as RegAppTable;
        if (!appTbl.Has(regapptablename))
        {
            RegAppTableRecord appTblRcd = new RegAppTableRecord();
            appTblRcd.Name = regapptablename;
            appTbl.Add(appTblRcd);
            trans.AddNewlyCreatedDBObject(appTblRcd, true);
        }
        trans.Commit();
    }
    return;
}
#endregion
[CommandMethod("mydra")]
public static void mydra()
{
    // 获取当前数据库
    Document acDoc = Application.DocumentManager.MdiActiveDocument;
    Database acCurDb = acDoc.Database;
    // Start a transaction启动事务
    using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
    {
        // Open the Block table for read以读模式打开块表
        BlockTable acBlkTbl;
        acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,
        OpenMode.ForRead) as BlockTable;
        // Open the Block table record Model space for write
        // 以写模式打开块表记录ModelSpace
        BlockTableRecord acBlkTblRec;
        acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
        OpenMode.ForWrite) as BlockTableRecord;
        // Create the radial dimension创建半径标注
        RadialDimension acRadDim = new RadialDimension();
        acRadDim.Center = new Point3d(0, 0, 0);         //圆心
        acRadDim.ChordPoint = new Point3d(5, 5, 0);     //标注点
        acRadDim.LeaderLength = 5;                      //引线长度
        acRadDim.DimensionText= "S<>";                  //标注内容
        acRadDim.TextPosition = new Point3d(5, 5, 0);   //文字放置位置
        acRadDim.DimensionStyle = acCurDb.Dimstyle;     //标注样式
        acRadDim.Dimscale = scal;                       //全局比例
        acRadDim.Dimlfac = sca;                         //线型比例
        // 添加新对象到模型空间和事务                
        CheckRegApp("ACAD_DSTYLE_DIMRADIAL_EXTENSION");//自定义函数检查RegApp名字是否存在，不存在就添加regApp名字
        ResultBuffer resBuf = new ResultBuffer();
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataRegAppName, "ACAD_DSTYLE_DIMRADIAL_EXTENSION"));
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 387));
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 1));
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 388));
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataReal, 6.26953));//圆弧的开始角度
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataInteger16, 390));
        resBuf.Add(new TypedValue((int)DxfCode.ExtendedDataReal, 2.67146));//圆弧的结束角度
        acRadDim.XData = resBuf;
        acBlkTblRec.AppendEntity(acRadDim);
        acTrans.AddNewlyCreatedDBObject(acRadDim, true);
        // 提交修改，关闭事务
        acTrans.Commit();
    }
}