SKCanvasView event args contains only Pressed action type

user_871946 0
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My Sample custom control inherits from the SKCanvaView and overrides the OnTouch method. It simple prints into the Debug stream action type, however, the action type is always the type of Pressed.

From my understanding, I should get action types like Pressed, Released, Moved, Cancel. Why I'm getting only the Pressed action type?

Version information:

Xamarin.Forms v5.0.0.2012
SkiaSharp.Views.Forms v2.80.2

Tested with Android device running in Hyper-V as well as a physical device, both with same results.

using SkiaSharp.Views.Forms;

namespace PurpleBlue.MobileApp.Controls
{
    public class SampleControl : SKCanvasView
    {
        public SampleControl()
        {
            EnableTouchEvents = true;
        }

        protected override void OnTouch(SKTouchEventArgs e)
        {
            System.Diagnostics.Debug.WriteLine($"SampleControl: {e.ActionType}");
        }
    }
}

Output

[ViewRootImpl] ViewRoot's Touch Event : ACTION_DOWN
[0:] SampleControl: Pressed
[ViewRootImpl] ViewRoot's Touch Event : ACTION_UP
[ViewRootImpl] ViewRoot's Touch Event : ACTION_DOWN
[0:] SampleControl: Pressed
[ViewRootImpl] ViewRoot's Touch Event : ACTION_UP
[ViewRootImpl] ViewRoot's Touch Event : ACTION_DOWN
[0:] SampleControl: Pressed
[ViewRootImpl] ViewRoot's Touch Event : ACTION_UP

Control used in view

<controls:SampleControl 
    Grid.Row="1"
    HorizontalOptions="Center"
    HeightRequest="60"
    WidthRequest="120"
    BackgroundColor="Aqua"
/>
skiasharp xamarin.forms xamarin .net c#
1 Answers

The devil is in the detail, one has to mark as handled in the event handler. Once one does it, magic happens and the app correctly handles the remaining action types. The correct version of the event handler is the following.

protected override void OnTouch(SKTouchEventArgs e)
{
    System.Diagnostics.Debug.WriteLine($"SampleControl: {e.ActionType}, mouse: {e.MouseButton}");

    e.Handled = true;
}
user_8719460
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