wpf - 需要能够使控件模板中定义的画布在单击对象以外的任何位置时不可见

Question

我有一个用户控件，其中有一个包含画布的控件模板：

<ControlTemplate x:Key="ListBoxItemTemplate"
                         TargetType="ListBoxItem">
            <Grid Width="30"
                  Height="30">
                <!-- IsHitTestVisible=False so you can select enemies when 
                the infotip is visible and overlaps other enemies
                -->
                <Canvas x:Name="Inspect"
                        Visibility="Collapsed"
                        IsHitTestVisible="False">
                    <Image Source="/Images/InspectBubble.png"
                           Width="250" />
                    <StackPanel Margin="20"
                                Width="200"
                                Orientation="Vertical">
                        <TextBlock Foreground="White"
                                   FontWeight="Bold"
                                   FontSize="9pt"
                                   Margin="2"
                                   Text="{Binding Path=PatientName}"
                                   HorizontalAlignment="Left" 
                                   VerticalAlignment="Top"/>
                        <TextBlock Foreground="White"
                                   FontWeight="Bold"
                                   FontSize="9pt"
                                   Margin="2"
                                   Text="{Binding Path=Icu.IcuName}"
                                   HorizontalAlignment="Left" 
                                   VerticalAlignment="Top"/>
                        <TextBlock Foreground="White"
                                   FontWeight="Bold"
                                   FontSize="9pt"
                                   Margin="2"
                                   Text="{Binding Path=Icu.IcuLocation}"
                                   HorizontalAlignment="Left" 
                                   VerticalAlignment="Top"/>
                        <TextBlock Foreground="White"
                                   FontWeight="Bold"
                                   FontSize="9pt"
                                   Margin="2"
                                   Text="{Binding Path=AgeDisplay}"
                                   HorizontalAlignment="Left" 
                                   VerticalAlignment="Top"/>
                        <TextBlock Foreground="White"
                                   FontWeight="Bold"
                                   FontSize="9pt"
                                   Margin="2"
                                   Text="{Binding Path=LOSDisplay}"
                                   HorizontalAlignment="Left" 
                                   VerticalAlignment="Top"/>

                    </StackPanel>

                    <Canvas.RenderTransform>
                        <TranslateTransform X="-150"
                                            Y="-150" />
                    </Canvas.RenderTransform>
                </Canvas>

                <ContentPresenter RenderTransformOrigin="0.5,0.5">
                    <ContentPresenter.RenderTransform>
                        <RotateTransform Angle="{Binding Angle}" />
                    </ContentPresenter.RenderTransform>
                </ContentPresenter>
                <Grid.RenderTransform>
                    <TranslateTransform X="{Binding Location.X}"
                                        Y="{Binding Location.Y}" />
                </Grid.RenderTransform>
            </Grid>
            <ControlTemplate.Triggers>
                <Trigger Property="IsSelected"
                         Value="True">
                    <Setter Property="Visibility"
                            Value="Visible"
                            TargetName="Inspect" />
                    <Setter Property="Panel.ZIndex"
                            Value="1" />
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>

As you can see the Canvas displays the object details when an object is selected - as defined in the Trigger. 当我单击对象外部的任何位置时，我希望画布变得不可见。我怎样才能做到这一点？