让UserControl能显示焦点状态

'set the control can display the focus status

    Protected Overrides Sub OnGotFocus(ByVal e As System.EventArgs)

        MyBase.OnGotFocus(e)

        Me.BorderStyle = Windows.Forms.BorderStyle.FixedSingle

    End Sub

    Protected Overrides Sub OnLostFocus(ByVal e As System.EventArgs)

        MyBase.OnLostFocus(e)

        Me.BorderStyle = Windows.Forms.BorderStyle.None

    End Sub