CODEWITHSUNDEEP
androidiosxamarintouch
Ferenc Dajka
Ferenc Dajka

Reputation: 1051

Touch events in custom renderer [XAMARIN]

I am overriding Xamarin's built in OnTouchEvent. I need the coordinates and the actions, the user creates. It properly emits Move, and Up actions, only if I move my finger on the screen.

It does not however: 1, emit anything, if I don't move my finger, only tap once (should be 1 Down and 1 Up event). 2, emit Down action, when I move my finger.

The XAML:

<renderers:CustomCollectionView
                                x:Name="ListItemsContaner"
                                IsGrouped="True"
                                ItemsSource="{Binding GroupedItems}">
                        <CollectionView.GestureRecognizers>
                            <TapGestureRecognizer NumberOfTapsRequired="1" Tapped="OnClicked"></TapGestureRecognizer>
                        </CollectionView.GestureRecognizers>
    
                            ...
                            
                        </renderers:CustomCollectionView>

Here's the renderer's code

using Android.Views;
using AppTourism.Droid.Renderers;
using AppTourism.Renderers;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(CustomCollectionView), typeof(CustomCollectionViewRenderer))]
namespace AppTourism.Droid.Renderers
{
    public class CustomCollectionViewRenderer : CollectionViewRenderer, ICustomCollectionViewRenderer
    {
        public CustomCollectionViewRenderer(Android.Content.Context context) : base(context) { }


        public override bool OnTouchEvent(MotionEvent e)
        {
            System.Console.WriteLine(e.Action);
            System.Console.WriteLine(e.RawX + " " + e.RawY);
            return base.OnTouchEvent(e);
        }

        
    }
}

Upvotes: 0

Views: 501

Answers (1)

Adrain
Adrain

Reputation: 1944

It seems a bug on not only collectionview but also other views in xamarin, like this issue said:

https://github.com/xamarin/Xamarin.Forms/issues/7159

The workaround is use TapGestureRecognizer instead:

<CollectionView.GestureRecognizers>
                <TapGestureRecognizer NumberOfTapsRequired="1" Tapped="OnClicked"></TapGestureRecognizer>
            </CollectionView.GestureRecognizers>

EDIT:

You can override the DispatchTouchEvent

 public override bool DispatchTouchEvent(MotionEvent e)
        {System.Console.WriteLine(e.Action);
            System.Console.WriteLine(e.RawX + " " + e.RawY);
            return base.DispatchTouchEvent(e);}

enter image description here

Upvotes: 1

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