主题：加载表后为什么非要重新打开一次窗口才能发挥作用？

我是用以下代码打开窗口的，要实现上述代码的目的，需要怎么修改

If e.Node.Level = 1 Then
    Dim tab As WinForm.TabControl = e.Form.Controls("TabControl1")
    If tab.TabPages(e.Node.Text) IsNot Nothing Then
        tab.SelectedPage = tab.TabPages(e.Node.Text)
    Else
        Dim Name As String = e.Node.Text
        tab.TabPages.Add(name,name)
        Dim pb = tab.BaseControl
        Forms(Name).OPEN(-1000,-1500)
        Forms(Name).BaseForm.TopLevel = False
        Forms(Name).BaseForm.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
        Forms(Name).BaseForm.Dock = System.Windows.Forms.DockStyle.Fill
        PB.TabPages(name).Controls.Clear
        PB.TabPages(name).Controls.add(Forms(Name).BaseForm)
        tab.SelectedPage = tab.TabPages(name)
        vars("父tab") = tab
    End If
End If