在窗體的Closing事件中加入確認代碼。
private void Form1_FormClosing(object sender, FormClosingEventArgs e) { if (MessageBox.Show("您確認退出嗎?", "www.cnblogs.com/jihua", MessageBoxButtons.YesNoCancel) == System.Windows.Forms.DialogResult.Yes) { Dispose(); Application.Exit(); } else { e.Cancel = true; } }