[CommandMethod("cre")] 
        public void cre() 
        { 
            int i,j; 
            MText mt = new MText(); 

            TypedValue[] ty = new TypedValue[] { new TypedValue((int)DxfCode.Text,mt) }; 
            SelectionFilter sel = new SelectionFilter(ty); 
            SelectionFilter fil = new SelectionFilter(ty); 
            Editor ed = Application.DocumentManager.MdiActiveDocument.Editor; 
            PromptSelectionOptions re = new PromptSelectionOptions(); 
            PromptSelectionResult su = ed.GetSelection(re ); 
            if (su.Status != PromptStatus.OK) 
            { 
                return; 
            } 
            Autodesk.AutoCAD.EditorInput.SelectionSet SS = su.Value; 
            ObjectId[] idArray; 
            idArray = SS.GetObjectIds(); 
            i = idArray.Length; 
            StreamWriter strw = File.CreateText("d:\\temp\\Mmmmtest.txt"); 
            strw.WriteLine(i.ToString()); 
            
            
            for (j = 0; j <= i - 1; j++) 
            { 
                //try 
                //{ 
                if (idArray[j].GetObject(OpenMode.ForRead).GetType() is MText) 
                { 


                    mt = (MText)idArray[j].GetObject(OpenMode.ForRead); 
                    strw.WriteLine(mt.Contents.ToString()); 
                } 
                else 
                { 
                    continue; 
                } 
                    
              

              
                
            } 
            strw.Close(); 
          

        } 
这编译都通过了，是关于autocad的二次开发的，目的是将text读取到txt文件中！！但是一再cad中用连autocad都直接挂了！！！说出现致命错误！高手救救火啊！！