touch two screen elements windows 10 universal

Question

I have been asked to create a feature which requires you to simultaneously press two independent areas (buttons) of a touch interface. I have not been able to find out if this is possible (OK google)

I would assume you can simply intercept the touchstart events, if the device supports multi touch... and hook in that way, but I have not tried this, and I don't know if the second touchstart will be fired?

Does anyone have an experience with this?

Answer 1

It is possible to manipulate two elements with touch interactions simultaneously. However, there is no touchstart event in UWP. Instead, you may need use Manipulation events. And following is a simple sample:

XAML:

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Rectangle Name="BlueRectangle"
           Width="200" Height="200" Fill="Blue"
           ManipulationMode="All" HorizontalAlignment="Left" VerticalAlignment="Top" />
    <Rectangle Name="RedRectangle"
           Width="200" Height="200" Fill="Red"
           ManipulationMode="All" HorizontalAlignment="Right" VerticalAlignment="Bottom" />
</Grid>

Code-Dehind:

public sealed partial class MainPage : Page
{
    private TranslateTransform dragBlueTranslation;
    private TranslateTransform dragRedTranslation;

    public MainPage()
    {
        this.InitializeComponent();

        dragBlueTranslation = new TranslateTransform();

        BlueRectangle.RenderTransform = this.dragBlueTranslation;

        BlueRectangle.ManipulationDelta += (s, e) =>
        {
            dragBlueTranslation.X += e.Delta.Translation.X;
            dragBlueTranslation.Y += e.Delta.Translation.Y;
        };

        dragRedTranslation = new TranslateTransform();

        RedRectangle.RenderTransform = this.dragRedTranslation;

        RedRectangle.ManipulationDelta += (s, e) =>
        {
            dragRedTranslation.X += e.Delta.Translation.X;
            dragRedTranslation.Y += e.Delta.Translation.Y;
        };
    }
}

And if you just need to detect the press, you can try with Tapped event. For more info, please see Touch interactions.