在敲代码的时候，为了更加人性化的设计，我们在用户退出系统之前需要进行提示，如下图：

实现方法分为两大类：窗体事件和控件事件，下面就一一展示：

一、FormClosing事件（又分以下几种方法）

a.

    Private Sub frmPractise_FormClosing(ByVal sender As Object,ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If MessageBox.Show("确定退出吗？","退出确认",MessageBoxButtons.YesNo,MessageBoxIcon.Question) = Windows.Forms.DialogResult.No Then
            e.Cancel = True
        End If
    End Sub

b.

    Private Sub Practise_FormClosing(ByVal sender As Object,ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If MsgBox("确定退出吗？",MessageBoxButtons.OKCancel,"退出确认") = Windows.Forms.DialogResult.Cancel Then
            e.Cancel = True
        End If
    End Sub

c.

    Private Sub Practise_FormClosing(ByVal sender As Object,ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        Dim p As Integer
        p = MsgBox("你真的要退出系统吗？",MsgBoxStyle.OkCancel,"提示")
        If p = 2 Then
            e.Cancel = True
        End If
    End Sub

d.(最为简单)

    Private Sub Practise_FormClosing(ByVal sender As Object,ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If MsgBox("你确认要退出程序吗？","退出提示") = MsgBoxResult.Cancel Then e.Cancel = True
    End Sub

以上只是点击窗口关闭按钮时的用法，若直接在窗体控件上点击退出时，可以用以下方式实现：

二、Button_Click事件

    Private Sub btnQuit_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles btnQuit.Click

        If MsgBox("是否要退出系统？",MsgBoxStyle.YesNo + MsgBoxStyle.Question,"提示") = MsgBoxResult.Yes Then
            Application.Exit()
        End If

    End Sub