场景：通常情况下，将窗体add进TabControl，但是关闭TabItem的时候，并没有触发内嵌窗体的关闭窗体事件，但有时候又希望触发该事件。

处理：为了方便，最好在add窗体的,TabItem的.Text设置与Form一样的Text

Private Sub NavSuperTabControl_TabItemClose(ByVal sender As Object, ByVal e As DevComponents.DotNetBar.SuperTabStripTabItemCloseEventArgs) Handles NavSuperTabControl.TabItemClose
Dim tabitem As SuperTabItem
For Each tabitem In NavSuperTabControl.Tabs
If tabitem.Name = e.Tab.Tag Then
NavSuperTabControl.SelectedTab = tabitem
Exit For
End If
Next
Dim frm As Form = Me.NavSuperTabControl.SelectedPanel.Controls.Find(e.Tab.Tag, False)(0)
frm.Close()
End Sub