when i use a popup, it seems to hang around. in the code below i attach a popup to a textBox using by overriding the control template, and make the popup appear when the TextBox has focus. When you tab to the next on screen element the popup goes away, but if you just alt-tab to a different application the popup stays there in the foreground. how do i get rid of it?
<Window x:Class="DropDownPicker.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300">
<Grid>
<StackPanel>
<TextBox Text="hello">
<TextBox.Style>
<!-- Simple TextBox -->
<Style
TargetType="{x:Type TextBox}">
<Setter
Property="KeyboardNavigation.TabNavigation"
Value="None" />
<Setter
Property="FocusVisualStyle"
Value="{x:Null}" />
<Setter
Property="AllowDrop"
Value="true" />
<Setter
Property="Template">
<Setter.Value>
<ControlTemplate
TargetType="{x:Type TextBox}">
<Grid>
<Border
x:Name="Border"
Background="{DynamicResource WindowBackgroundBrush}"
BorderBrush="{DynamicResource SolidBorderBrush}"
BorderThickness="1"
Padding="2"
CornerRadius="2">
<Grid>
<!-- The implementation places the Content into the ScrollViewer. It must be named PART_ContentHost for the control to function -->
<ScrollViewer
Margin="0"
x:Name="PART_ContentHost"
Style="{DynamicResource SimpleScrollViewer}"
Background="{TemplateBinding Background}" />
<Popup
x:Name="thePopup"
IsOpen="False">
<Border
BorderBrush="Red"
BorderThickness="5">
<TextBlock
Text="Hellssss" />
</Border>
</Popup>
</Grid>
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger
Property="IsFocused"
Value="True">
<Setter
TargetName="thePopup"
Property="IsOpen"
Value="True" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</TextBox.Style>
</TextBox>
<TextBox
Text="ssss" />
</StackPanel>
</Grid>
</Window>