Question

mdi子窗口关闭时触发父窗口的什么事件

Answer 1

在formclosing事件里进行判断。

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if(e.CloseReason = CloseReason.MdiFormClosing)
//做该做的事
else if(e.CloseReason = CloseReason.UserClosing )
//弹出消息
else
//做该做的事
}