1、Private Sub Form1_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 IfEnd Sub

2、Private Sub Form1_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 IfEnd Sub        3、Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing    Dim p As Integer    p = MsgBox("你真的要退出游戏吗？", MsgBoxStyle.OkCancel, "游戏提示")    If p = 2 Then        e.Cancel = True    End IfEnd Sub

4、最简单的代码：Private Sub Form1_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？", MsgBoxStyle.OkCancel, "退出提示") = MsgBoxResult.Cancel Then e.Cancel = TrueEnd 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：

    Public Sub checkExit()        If (MessageBox.Show("您确定要退出系统吗？", "确认", MessageBoxButtons.YesNo, MessageBoxIcon.Question) = Windows.Forms.DialogResult.OK) Then            Me.Close()            Application.Exit()        End If    End Sub