听儿童MenuItem点击 [英] Listen to child MenuItem Click

问题描述

是否有一种方法可以在按下子菜单项时通知父级菜单项。
例如，我有

 < MenuItem Name ='a'> 
< MenuItem Name ='b'Header ='...'/> 
< / MenuItem> 
  

如何在b被点击时将其添加到要通知的事件处理程序。
理想情况下，Click事件将是隧道或气泡事件，但事实并非如此。
我想到的解决方案是听b上的Click事件并将其转发到一个，但这似乎相当沉重。
有更好的解决方案吗？

解决方案

MenuItem.Click 是一个路由事件（它起泡），所以你可以订阅它

XAML：

 < MenuItem Name ='a'Click ='OnMenuItemClicked'> 
< MenuItem Name ='b'Header ='...'/> 
< / MenuItem> 
  

C＃：

 code> private void OnMenuItemClicked（object sender，RoutedEventArgs e）
 {
 MenuItem item = e.OriginalSource as MenuItem; 
 if（null！= item）
 {
 //处理菜单项点击这里
} 
} 
  / pre> 
 
 
诀窍是使用 RoutedEventArgs.OriginalSource 而不是 sender 。这指向最初触发事件的控件。
 
Is there a way for a parent MenuItem to be notified when a child MenuItem is pressed.
For example, I you have
<MenuItem Name='a'>
    <MenuItem Name='b' Header='...'/>
</MenuItem>
how can I add an event handler to a to be notified when b is clicked.
Ideally, the Click event would be either a tunnel or bubble event but this is not the case.
The solution I have in mind is to listen to the Click event on b and forward it to a but this seems pretty heavy handed.
Is there a better solution?
解决方案
MenuItem.Click is a routed event (it bubbles up), so you can just subscribe to it on the first MenuItem and be notified of all children at the same time.

XAML:
<MenuItem Name='a' Click='OnMenuItemClicked'>
    <MenuItem Name='b' Header='...' />
</MenuItem>
C#:
private void OnMenuItemClicked(object sender, RoutedEventArgs e)
{
    MenuItem item = e.OriginalSource as MenuItem;
    if(null != item)
    {
        // Handle the menu item click here
    }
}
The trick is to use RoutedEventArgs.OriginalSource, rather than sender. This points to the control that originally fired the event.

                        
这篇关于听儿童MenuItem点击的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！