MouseUp not firing on child StackPanels

问题

I cannot seem to find a way to achieve smth very simple:

I have an ItemsControl with a UniformGrid inside of it, that arranges items by a DataTemplate:

<ItemsControl ItemTemplate="{StaticResource ResourceKey=tmMapCell}"  
        MouseUp="wpSubMap_MouseUp" BorderThickness="1" BorderBrush="DarkGray">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <UniformGrid Columns="8" Rows="6" />
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
</ItemsControl>

Here's the cell template:

<DataTemplate x:Key="tmMapCell">
    <Border BorderBrush="DimGray" BorderThickness="1" Margin="1" Background="Gainsboro" Visibility="{Binding Path=vMapCell}" >
        <StackPanel VerticalAlignment="Center">
            <TextBlock Margin="2,4,2,2" TextAlignment="Center" Text="{Binding Path=sCell0}" FontWeight="Bold" />
            <StackPanel>
                <StackPanel.Background><SolidColorBrush Color="{Binding Path=cColorB}" /></StackPanel.Background>
                <TextBlock Margin="2,1,2,0" TextAlignment="Center" Text="{Binding Path=sCell1}" FontWeight="{Binding Path=fntWt}">
                    <TextBlock.Foreground><SolidColorBrush Color="{Binding Path=cColorF}" /></TextBlock.Foreground>
                </TextBlock>
                <TextBlock Margin="2,1,2,0" TextAlignment="Center" Text="{Binding Path=sCell2}" FontWeight="{Binding Path=fntWt}">
                    <TextBlock.Foreground><SolidColorBrush Color="{Binding Path=cColorF}" /></TextBlock.Foreground>
                </TextBlock>
            </StackPanel>
            <TextBlock Margin="2" TextAlignment="Center" FontWeight="Normal" Text="{Binding Path=tElapsed, StringFormat='HH:mm:ss'}"></TextBlock>
            <StackPanel Margin="0" *MouseUp*="Svc_MouseUp" Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Bottom" Background="White" Visibility="{Binding Path=vSvcs}">
                <Border BorderBrush="DimGray" BorderThickness="1" Margin="2,2,0,2">
                    <StackPanel Name="spSvcGrn" *MouseUp*="Svc_MouseUp">
                        <TextBlock Name="txSvcGrn" Height="14" Width="16" TextAlignment="Center" FontWeight="Normal" Text="{Binding Path=sSvc1}" Background="Lime" Visibility="{Binding Path=vSvc1}" />
                    </StackPanel>
                </Border>
                <Border BorderBrush="DimGray" BorderThickness="1" Margin="2,2,0,2">
                    <StackPanel Name="spSvcOra" *MouseUp*="Svc_MouseUp">
                        <TextBlock Name="txSvcOra" Height="14" Width="16" TextAlignment="Center" FontWeight="Normal" Text="{Binding Path=sSvc2}" Background="Orange" Visibility="{Binding Path=vSvc2}" />
                    </StackPanel>
                </Border>
                <Border BorderBrush="DimGray" BorderThickness="1" Margin="2,2,2,2">
                    <StackPanel Name="spSvcYel" *MouseUp*="Svc_MouseUp">
                        <TextBlock Name="txSvcYel" Height="14" Width="16" TextAlignment="Center" FontWeight="Normal" Text="{Binding Path=sSvc3}" Background="Yellow" Visibility="{Binding Path=vSvc3}" />
                    </StackPanel>
                </Border>
            </StackPanel>
        </StackPanel>
    </Border>
</DataTemplate>

This results in a nice layout, filled with cells according to info, coming from a DB (top left corner shown):

I need to trap clicks on the little squares within each cell (highlighted in G,O,Y). I already have a MouseUp handler for entire ItemsControl (wpSubMap_MouseUp), which handles clicks on the cells themselves and works properly. I'm trying to add new handlers to individual cell items, and that's where everything stops working:

If i leave only Svc_MouseUp - for the outer StackPanel, surrounding all squares, it fires each time; but the problem is detecting, which square was actually clicked on.

If i enable Svc_MouseUp - for inner StackPanels, wrapping individual squares, they don't fire at all!?

P.S. Both MouseUp handlers use the following pattern to prevent re-entrance:

private void    Svc_MouseUp( object sender, MouseButtonEventArgs e )
{
    if(  bMouseUp  )    return;

    Cursor  cur=    this.Cursor;

    try
    {
        this.Cursor=    Cursors.Wait;
        bMouseUp=   true;

        ..  /// do smth useful
    }
    finally
    {
        e.Handled=  true;
        bMouseUp=   false;
        this.Cursor=    cur;
    }
}

What am i missing here? What makes handler firing behavior so different for inner StackPanels?
And how should i efficiently implement hit detection for inner StackPanels?

来源：https://stackoverflow.com/questions/18729145/mouseup-not-firing-on-child-stackpanels