CODEWITHSUNDEEP
c#xaml
Roby
Roby

Reputation: 23

XAML hittesting

In the model I have a observable collection of objects. With an ItemsControl (and UserControl) I display these elements (shapes).

Now I want to do hittesting on the parent canvas.

For example when I execute this code:

HitTestResult result = VisualTreeHelper.HitTest(allContent, new Point(70, 340));

I get a HitTestResult, but I want to get the object in the model representing this "clicked" shape.

Is there a possibility of getting the object?

Upvotes: 1

Views: 434

Answers (1)

Ben Von Handorf
Ben Von Handorf

Reputation: 2336

To get to the DataContext that is bound to the ListBoxItem in question, I do this:

HitTestResult result = VisualTreeHelper.HitTest( itemsContainer, position ) ;
FrameworkElement currentElement = result.VisualHit as FrameworkElement ;

while( (currentElement is ListBoxItem)==false
    && currentElement!=itemsControlElement 
    && currentElement!=null)
{
    currentElement = VisualTreeHelper.GetParent(currentElement) as FrameworkElement ;
}

if( currentElement != null )
{
    object dataSource = currentElement.DataContext ;
}

If you switch the stack walk to look for your UserControl instead of a ListBoxItem and change the itemsControlElement to be whatever your ItemsControl container is, it should prevent runaway walks of the visual tree.

Upvotes: 2

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