vb.net中如何实现：在运行时关闭窗体，弹出对话框提示是否要关闭

小爱

    Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
        Dim myti As Integer
        myti = MsgBox("确定退出此界面？", MsgBoxStyle.Question + MsgBoxStyle.YesNo, "提示")
        Select Case myti
            Case MsgBoxResult.Yes
                e.Cancel = False
            Case Else
                e.Cancel = True
        End Select
    End Sub