Lost focus event in pop up not working in user control wpf
<p>I have a pop up control inside a UserControl:</p>

<pre><code>&lt;UserControl ....&gt;
&lt;Popup x:Name="popUp" IsOpen="False" AllowsTransparency="True" LostFocus="popUp_LostFocus"&gt;
....
&lt;/Popup&gt;
&lt;/UserControl&gt;
</code></pre>

<p>The popup has a LostFocus Event:</p>

<pre><code>private void popUp_LostFocus(object sender, RoutedEventArgs e)
{
    ...
}
</code></pre>

<p>But when I use the user control in a Window and the pop up lost the focus, the event not working.</p>