主题：窗口类型

可以取巧变通，如

Dim frm = forms("窗口2")
frm.open
msgbox(frm.panel Is Nothing)
Dim nfrm As new windows.forms.form
Dim cs = frm.panel.controls
For i As Integer = cs.count-1 To 0 Step -1
    nfrm.controls.add(cs(i))
Next
nfrm.show