为何加入多义线总出错

tcsl9621 · 发表于 2006-8-7 21:52:00

&nbspublic Function addpl()
      Dim db As Database = HostApplicationServices.WorkingDatabase()
      Dim trans As Transaction = db.TransactionManager.StartTransaction()
      MsgBox("0")
      Try
         Dim pl As New Circle(New Point3d(0, 0, 0), Vector3d.ZAxis, 100)
         MsgBox("1")
         Dim bt As BlockTable = trans.GetObject(db.BlockTableId, OpenMode.ForRead)
         MsgBox("2")
         Dim btrid As ObjectId = bt.Item(BlockTableRecord.ModelSpace)
         Dim btr As BlockTableRecord = trans.GetObject(btrid, OpenMode.ForWrite)
         MsgBox("3")
         Dim ObjId As ObjectId
         MsgBox("4")
         ObjId = btr.AppendEntity(pl)
         MsgBox("5")
         trans.AddNewlyCreatedDBObject(pl, True)
         MsgBox("6")
         trans.Commit()
      Catch ex As Exception
         MsgBox("pl error.")
      Finally
         trans.Dispose()
      End Try
End Function
上面程序中红色代码总出错。请高手指点。

tcsl9621 · 发表于 2006-8-7 21:59:00

我可按照教程一个字都不差，不知为什么就是不行。

mkhsj929 · 发表于 2006-8-8 14:47:00

好像是这样吧？
Dim btr As BlockTableRecord = trans.GetObject(db.CurrentSpaceID, OpenMode.ForWrite)

tcsl9621 · 发表于 2006-8-8 23:16:00

谢谢楼上的弟兄回复。但我试了还是不行。我将OpenMode.ForWrite换成OpenMode.ForRead就好了，但下面出错。因为不是以写方式打开的。是什么毛病？

mkhsj929 · 发表于 2006-8-11 09:43:00

这是我在C＃里面的代码：（成功的）复制代码

sieben · 发表于 2006-8-15 16:35:00

            Dim btr As BlockTableRecord = trans.GetObject(btrid, OpenMode.ForWrite)

改写为下面试试
         Dim btr As BlockTableRecord = (BlockTableRecord)trans.GetObject(btrid, OpenMode.ForWrite)
我的意思是加一步显式转换,我忘了VB是不是这样转换了,C#是