Canvas manipulation event not firing until after first try

Question

I'm trying to animate a canvas by swiping using ´ManipulationDelta`. The problem is simple. when I run the app, the only time the manipulation event is not fired is at the first try. If I tap (or swipe) anywhere in the canvas once, then the second time it works until the application is restarted.

This is my XAML code:

<Canvas Name="rootCanvas" Style="{StaticResource rootCanvas}" Hold="rootCanvas_Hold" ManipulationDelta="rootCanvas_ManipulationDelta" ManipulationCompleted="rootCanvas_ManipulationCompleted">
    <Canvas.Resources>
        <Storyboard x:Name="menuAnimation">
            <DoubleAnimation Duration="0:0:0.2" To="0" Storyboard.TargetProperty="(Canvas.Left)" Storyboard.TargetName="rootAnimation" d:IsOptimized="True" />
        </Storyboard>
    </Canvas.Resources>
    <Canvas Name="rootAnimation">
        <Grid x:Name="rootContainer" DataContext="{Binding}" Style="{StaticResource rootContainer}">
            ...
        </grid>
    </Canvas>
</Canvas>

And this is my code in C#

private void rootCanvas_ManipulationDelta(object sender, System.Windows.Input.ManipulationDeltaEventArgs e)
{
    if (e.DeltaManipulation.Translation.X > 25 && !menu.IsMenuOpen())
    {
        MoveViewWindow(150);
        hintActive = false;
        menu.SetMenuOpen();
        return;
    }
    else if (e.DeltaManipulation.Translation.X < (-25) && menu.IsMenuOpen())
    {
        MoveViewWindow(0);
        hintActive = false;
        menu.SetMenuClosed();
        return;
    }
}

private void rootCanvas_Hold(object sender, System.Windows.Input.GestureEventArgs e)
{
    if (!menu.IsMenuOpen())
    {
        hintActive = true;
        MoveViewWindow(25);
    }
    return;
}

I have a rootCanvas_ManipulationCompleted where the breakpoint gets hit even if the ManipulationDelta and Hold breakpoints aren't.

Any ideas?

Answer 1

Try the command:

rootCanvas.Focus();

This will set focus to the canvas you are hitting, just pop this event in the load method of the page.