Is there a way to get click location within GraphicsView?

[jtomes123]

Hi, I need to do some custom functionality and I want to draw objects that the user would click on and some other click based functionality. How could I get click position in TapGestureRecognizer or ClickGestureRecognizer or is there a different way to handle this?

[mstasak]

Using OnStartInteraction/OnEndInteraction, like (XAML)::

            <GraphicsView Grid.Row="5"
                          Drawable="{StaticResource drawable}"
                          HeightRequest="200"
                          WidthRequest="400"
                          StartInteraction="OnStartInteraction"
                          EndInteraction="OnEndInteraction"/>

with (C#):

private void OnStartInteraction(object Sender, TouchEventArgs evt) {
   PointF firstPoint = evt.Touches.FirstOrDefault();
   string msg = $"Touch/click at {firstPoint}";
   CounterLabel.Text = msg;
}
private void OnEndInteraction(object Sender, TouchEventArgs evt) {
   PointF lastPoint = evt.Touches.LastOrDefault();
   string msg = $", released at {lastPoint}";
   CounterLabel.Text += msg;
}

You may need refinements to detect things like EndInteraction due to moving mouse outside the GraphicsView's edges.

[mstasak]

A more elegant approach would be to use a TapGestureRecognizer, but when I tried it I received the event but it contained no click/tap location data.

            <GraphicsView Grid.Row="5"
                          Drawable="{StaticResource drawable}"
                          HeightRequest="200"
                          WidthRequest="400">
                <GraphicsView.GestureRecognizers>
                    <TapGestureRecognizer Tapped="OnTapGestureRecognizerTapped"
                              NumberOfTapsRequired="1" />
                </GraphicsView.GestureRecognizers>
            </GraphicsView>

   private void OnTapGestureRecognizerTapped(object sender, EventArgs args) {
	  // Handle the tap
	  CounterLabel.Text += $"Tap detected at {((TappedEventArgs)args).Parameter}"; //Parameter == null
   }