运行一段vb代码后，cad保存时提示“文档 Drawing1.dwg 正在执行命令

arthurfy · 发表于 2012-2-26 10:24:00

大家好，我在cad里运行下面的代码生成一个属性块，生成后，cad保存时提示“文档 Drawing1.dwg 正在执行命令。
按回车键取消或 [重试(R)]: ”
'' 获得当前文档和数据库 Get the current document and database
      Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument
      Dim acCurDb As Database = acDoc.Database
      ''启动一个事务 Start a transaction
      Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()
         '' 以只读方式打开块表 Open the Block table for read
         Dim acBlkTbl As BlockTable
         acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, _
                                       OpenMode.ForRead)
         '文档加锁
         acDoc.LockDocument()
         '' 以写方式打开模型空间块表记录 Open the Block table record Model space for write
         Dim acBlkTblRec As BlockTableRecord
         acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _
                                          OpenMode.ForWrite)
         ''创建属性块 Create a single-line text object
         Dim attdef As AttributeDefinition = New AttributeDefinition()
         attdef.Position = New Point3d(0.0, 0.0, 0.0)
         attdef.Height = 8.0 '//设置文字高度
         attdef.Rotation = 0.0 '//设置文字旋转角度
         attdef.HorizontalMode = TextHorizontalMode.TextMid '//设置水平对齐方式
         attdef.VerticalMode = TextVerticalMode.TextVerticalMid '//设置垂直对齐方式
         attdef.Prompt = "Room Number:" '//设置属性提示
         attdef.TextString = "0000" '//设置属性的缺省值
         attdef.Tag = "NUMBER" '//设置属性标签
         attdef.Invisible = False '//设置不可见选项为假
         attdef.Verifiable = False '//设置验证方式为假
         attdef.Preset = False '//设置预置方式为假
         attdef.Constant = False '//设置常数方式为假
         acBlkTblRec.AppendEntity(attdef)
         acTrans.AddNewlyCreatedDBObject(attdef, True)
         '解锁文档
         acDoc.LockDocument.Dispose()
         ''保存更改并销毁事务 Save the changes and dispose of the transaction
         acTrans.Commit()
      End Using
      acDoc = Nothing
      acCurDb.Dispose()
请问是什么原因，我文档加锁后也解锁了啊