可显示/隐藏左边控件的Splitter

可显示/隐藏左边控件的Splitter(3)             End If
        Next

        If Not targetctrl Is Nothing Then
            Dim tt As ToolTip = CType(lbl.Tag, ToolTip)
            If lbl.Text = "3" Then
                lbl.Text = 4
                tt.SetToolTip(lbl, "显示左边的的控件")
                targetctrl.Visible = False
            Else
                lbl.Text = 3
                tt.SetToolTip(lbl, "隐藏左边的的控件")
                targetctrl.Visible = True
            End If
        End If
    End Sub

    Private Shared Sub splitter_Resize(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim sl As Splitter = CType(sender, Splitter)
        Dim lbl As Label = sl.Controls(0)
        lbl.Location = New Point(-3.5, sl.Height / 2 - lbl.Height)
    End Sub
End Class

使用时，在窗体的初始化代码中加入如下所示的红色代码即可：
    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化