事件参数-它们应该反映事件发生时的状态快照还是实时数据?

谢谢您,
本

代码示例

protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
{
   // before MessageBox display, e.ButtonState = Pressed
   MessageBox.Show("OnPreviewMouseLeftButtonDown");
      
   // now, e.ButtonState = Released 
   base.OnPreviewMouseLeftButtonDown(e);
}