Problems with event bubbeling (ScrollViewer)

I have a problem with bubbeling events. I manage to bubble events in borders, grid, stackpanel, but not in a ScrollViewer

If you look at the example below you will notice that when you click the TextBlock the event is bubbeled up to the Grid. But when I include the ScrollViewer the event stops here and is not sent up to the Grid.

Does anyone now whay this happends and if it can be fixed? I really need to be able to bubble events through a ScrollViewer as I use it all the time.

<Grid MouseLeftButtonDown="Grid_MouseLeftButtonDown">
        <!--<ScrollViewer MouseLeftButtonDown="ScrollViewer_MouseLeftButtonDown">-->
            <StackPanel Orientation="Vertical" MouseLeftButtonDown="StackPanel_MouseLeftButtonDown">
                <TextBlock Text="Click me to bubble an event" MouseLeftButtonDown="TextBlock_MouseLeftButtonDown"/>
            </StackPanel>
        <!--</ScrollViewer>-->
</Grid>


public partial class MainPage : UserControl
{
    public MainPage()
    {
        InitializeComponent();
    }

    private void Grid_MouseLeftButtonDown(object sender, MouseButtonEv开发者_StackOverflowentArgs e)
    {
        MessageBox.Show("LayoutRoot clicked");
    }


    private void ScrollViewer_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        MessageBox.Show("ScrollViewer clicked");
        e.Handled = false;
    }

    private void StackPanel_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        MessageBox.Show("StackPanel clicked");
        e.Handled = false;
    }

    private void TextBlock_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        MessageBox.Show("Textblock clicked");
        e.Handled = false;
    }
}

use AddHandler(yourDelegate, True); syntax for adding event handlers, which will ignore Handled flag set by other controls in the visual tree.

I had this problem and the fix posted by user572559 fixed my issue. For those that need it, below is what I did (modified for posting):

_scrollViewer = new ScrollViewer();
_scrollViewer.AddHandler(
    ScrollViewer.MouseLeftButtonDownEvent, 
    new MouseButtonEventHandler(OnMouseLeftButtonDown),
    true);
_scrollViewer.AddHandler(
    ScrollViewer.MouseLeftButtonUpEvent, 
    new MouseButtonEventHandler(OnMouseLeftButtonUp), 
    true);

...

    void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        ...
    }

    void OnMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        ...
    }

Also note that if you hare handling these you may be handling MouseMove as well. MouseMove worked for me without needing to do this, and it also does not seem to be supported in this fashion (not a bubbling event).

You can prevent e.Handled on MouseButtonEventArgs by overriding ScrollViewer like this

public sealed class ClickScrollViewer : ScrollViewer
{
    protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
    {
        this.Focus();
    }
}