获取画布之子

Question

I am manipulating Canvas delta, canvas has two children ( Rectangle and Thumb ). I want my manipulation delta to only work when I click on Rectangle . Is there a way I can get which Canvas child is clicked.

void rec_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
    var recSender = (Canvas)sender; // Get the Rectangle
    var rec=recSender.Children[1] as Rectangle;

    //if (e.OriginalSource is Rectangle)
    {            
        TranslateTransform ttSender = recSender.RenderTransform as TranslateTransform; // Get the Rectangle's RenderTransform (which is a TranslateTransform)

        ttSender.X += e.Delta.Translation.X;
        ttSender.Y += e.Delta.Translation.Y;
    }
}

Answer 1

I'm not sure if I understood your problem fully. I think you have to set the Property

 ManipulationMode="All"

of the child elements to be able to access them with e.OriginalSource. This will make the event bubble up the chain.

In my code it looks like this:

XAML

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
        <Canvas ManipulationMode="All"  ManipulationDelta="Canvas_ManipulationDelta" >
            <Rectangle ManipulationMode="All" Fill="Red" Width="100" Height="411"></Rectangle>
            <Ellipse ManipulationMode="All" Fill="Green" Width="400" Height="130"></Ellipse>
        </Canvas>
    </Grid>

CS:

 private void Canvas_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
        {
            var x = e.OriginalSource;    
        }

Now when I klick the ellipse I get:

So I got access to the object. Works on my machine running Windows 10, VS2015.