学习VB.net二次开发例程

湖面之舟

  <CommandMethod("GetCircle")> Public Sub GetCircle()
        Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
        '创建一个选择实体的选择集选项，并限制为只能选择圆(使用了AddAllowedClass函数）
        Dim entitySelectionOpts As PromptEntityOptions = New PromptEntityOptions("\nSelect Circle")
        entitySelectionOpts.SetRejectMessage("\nOnly Circles may be selected.")
        entitySelectionOpts.AddAllowedClass(GetType(Circle), True)
        '开始选择圆的过程
        Dim entitySelectionResult As PromptEntityResult = ed.GetEntity(entitySelectionOpts)
        '如果成功选择了一个圆，就在命令行显示圆的半径
        If entitySelectionResult.Status = PromptStatus.OK Then
            DispalyCircleRadius(entitySelectionResult.ObjectId)
        End If
    End Sub

    Private Sub DispalyCircleRadius(ByVal circleId As ObjectId)
        Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
        Dim trans As Transaction
        trans = ed.Document.TransactionManager.StartTransaction
        Dim selectedCircle As Circle = CType(trans.GetObject(circleId, OpenMode.ForRead), Circle)
        Application.ShowAlertDialog("选择的园半径为：" + selectedCircle.Radius.ToString)
        trans.Commit()
    End Sub

编译的时候，红色标示部分总是提示类型不能转换，请问大家遇到过吗？该怎么解决呢？

湖面之舟

已经解决，呵呵

是由于同一个解决方案中其它项目加载了2005的库文件

rdhhb

楼上的朋友。请问你是如何设置。NET环境的？能否教教我？谢谢