主窗口关闭时触发子窗口的关闭事件 wpf用户控件的关闭事件 wpf usercontrol 释放时触发关闭事件

/// <summary>
        /// 关闭窗口事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="cancelEventArgs"></param>
        private void OnClosing(object sender, CancelEventArgs cancelEventArgs)
        {
            MessageBox.Show("OnClosing 子窗口要被关闭了");
            // 析构
        } 
        /// <summary>
        /// 界面加载事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Scan_PassSite_Loaded(object sender, RoutedEventArgs e)
        {
            //添加关闭事件
            Window.GetWindow(this).Closing += OnClosing;
        }