在VB.NET2005中，执行以下代码设置当前图层时，如果引用了则没问题，如果没引用的话，最后一句会出错，谁能帮我处理一下？
dim myc as object
dim mydwg as object
dim aclay as object
Myc = GetObject(, "AutoCAD.Application")
If Err.Number 0 Then
Myc = CreateObject("AutoCAD.application", )
Err.Clear()
End If
Myc.Visible = True
Mydwg = Myc.ActiveDocument
For Each aclay In mydwg.layers
If aclay.name = "table" Then
Exit For
End If
Next
置顶卡
