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 If
End 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 If
End 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 If
End 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 = 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：
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
