how do i make that dang wpf popup go away?

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
                              开发者_Python百科      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>

Have you tried setting the StaysOpen property to False?

If StaysOpen is True, which is the default, it will stay open until the control is no longer in focus. If it is False it will stay open until a mouse or keyboard event occurs outside of the Popup control, which may be the case while alt-tabing. You might have to tweak it a bit to get it to behave like you want, but it may be a starting point.

I listened to the LostMouseCapture event and then set the StaysOpen property on the Popup to false

This is by-design; Window focus != Control focus, otherwise when you tabbed away from a window and came back, your cursor would jump back to the first control. If you want the pop up to be hidden when the window isn't active, you have to manually do this.

Similar question is asked here also: WPF Popup ZOrder

Check this:

http://chriscavanagh.wordpress.com/2008/08/13/non-topmost-wpf-popup/

Hope this help you!!