Question

I have a WPF 4 application where I have implemented Drag and Drop using the standard DragDrop.DoDragDrop approach, but Im doing it using touch instead of Mouse events.

My XAML for my Grid (that Im dragging) is as follows:

<Grid x:Name="LayoutRoot" 
      ManipulationStarting="ManipulationStarting" 
      ManipulationDelta="ManipulationDelta" 
      ManipulationCompleted="ManipulationCompleted"
      IsManipulationEnabled="True">
    <!-- children in here -->
</Grid>

Now the code behind is like this:

    private void ManipulationStarting(object sender, ManipulationStartingEventArgs e)
    {
        e.ManipulationContainer = this;
        e.Handled = true;
    }

    private void ManipulationDelta(object sender, ManipulationDeltaEventArgs e)
    {
        e.Handled = true;
        DragDrop.DoDragDrop(this, new DataObject(GetType(), this), DragDropEffects.Move);
    }

    private void ManipulationCompleted(object sender, ManipulationCompletedEventArgs e)
    {
        //completed stuff
    }

BUT when I try to drag with one finger while already dragging with another finger (different hands for example, which would simulate two people) the second touches don’t seem to register properly, infact, it seems that windows thinks that my two fingers are trying to scale (like a pinch gesture)…

Does anyone know a way to get around this?

Thanks a lot
Mark

Answer 1

For multi-touch, you’re going to want to use the Surface Toolkit for Windows Touch. It includes a drag-and-drop framework suitable for multi-touch scenarios. It includes a drag-and-drop framework. That link includes several how-to scenarios.