得到一个通知，当焦点更改在Silverlight 4？ [英] Getting a notification when focus changes in Silverlight 4?

问题描述

我想缺少调试的一些问题/额外的制表位。是否有某种全球性的事件，我可以附加到，这样我就可以登录该元素得到了集中每当更改焦点？谢谢！下面是我在做什么，现在，它工作得很好，但我仍然好奇，是否有另一种方式：

  DispatcherTimer定时器=新DispatcherTimer（）;
timer.Interval = TimeSpan.FromSeconds（0.2）;
timer.Tick + = onTick;
timer.Start（）;

// ...

私有对象LastFocusedElement;
私人无效onTick（对象发件人，EventArgs的）
{
    对象ELEM = FocusManager.GetFocusedElement（）;
    如果（LastFocusedElement！= ELEM）
    {
        LastFocusedElement = ELEM;
        System.Diagnostics.Debug.WriteLine（+++ FOCUS +++焦点改为：+ ELEM +（ELEM == NULL：（+ elem.GetType（）名+）））;
    }
}
 

解决方案

您应该可以订阅的GotFocus 事件的最顶层容器。我没有看到任何处理的标志 RoutedEventArgs 所以，据我所知道的，它应该总是达不到它

 ＆LT;用户控件...
             的GotFocus =UserControl_GotFocus＆GT;
    ＆LT;！ - 很多嵌套控件 - ＆GT;
＆LT; /用户控件＆GT;

私人无效UserControl_GotFocus（对象发件人，RoutedEventArgs E）
{
    对象ELEM = e.OriginalSource;
    System.Diagnostics.Debug.WriteLine（+++ FOCUS +++焦点改为：+ ELEM +（ELEM == NULL：（+ elem.GetType（）名+）））;
}
 

I'm trying to debug some issues with missing/extra tab stops. Is there some kind of global event that I can attach to so that I can log which element got focus whenever focus changes? Thanks! Here's what I'm doing right now, which works well enough, but I'm still curious as to whether there's another way:

DispatcherTimer timer = new DispatcherTimer();
timer.Interval = TimeSpan.FromSeconds(0.2);
timer.Tick += onTick;
timer.Start();

// ...

private object LastFocusedElement;
private void onTick(object sender, EventArgs e)
{
    object elem = FocusManager.GetFocusedElement();
    if(LastFocusedElement != elem)
    {
        LastFocusedElement = elem;
        System.Diagnostics.Debug.WriteLine("+++FOCUS+++ Focus changed to: " + elem + (elem == null ? "" : " (" + elem.GetType().Name + ")"));
    }
}

解决方案

You should be able to subscribe to the GotFocus event for the "top-most" container. I don't see any Handled flag for RoutedEventArgs so as far as I can tell, it should always reach it

<UserControl ...
             GotFocus="UserControl_GotFocus">
    <!-- Lots of Nested Controls -->
</UserControl>

private void UserControl_GotFocus(object sender, RoutedEventArgs e)
{
    object elem = e.OriginalSource;
    System.Diagnostics.Debug.WriteLine("+++FOCUS+++ Focus changed to: " + elem + (elem == null ? "" : " (" + elem.GetType().Name + ")"));
}

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