c# - Xamarin.Forms - Button Pressed & Released Event

Question

I want to my event to trigger when button pressed and released, but I can only find Click event in Xamarin.Forms.

I believe there must be some work around to get this functionality. My basic need is to start a process when button is pressed and stop when released. It seems to be a very basic feature but Xamarin.Forms doesn't have it right now.

I tried TapGestureRecognizer on button, but button is firing only click event.

MyButton.Clicked += (sender, args) =>
{
  Log.V(TAG, "CLICKED");
};

var tapGestureRecognizer = new TapGestureRecognizer();
tapGestureRecognizer.Tapped += (s, e) => {
    Log.V(TAG, "TAPPED");
};
MyButton.GestureRecognizers.Add(tapGestureRecognizer);

Keep in mind that I need those events to be working in Android and iOS togather.

Answer 1

Finally I got the solution suggested by @Jason. Here we go...

1. Create sub class of Xamarin.Forms.Button in PCL project, with event handling capability

   public class CustomButton : Button
   {
       public event EventHandler Pressed;
       public event EventHandler Released;
   
       public virtual void OnPressed()
       {
         Pressed?.Invoke(this, EventArgs.Empty);
       }
   
       public virtual void OnReleased()
       {
         Released?.Invoke(this, EventArgs.Empty);
       }
   }
   

2. Create platform specific button renderer in respective project

   For Andorid

   [assembly: ExportRenderer(typeof(Button), typeof(CustomButtonRenderer))]
   namespace WalkieTalkie.Droid.Renderer
   {
       public class CustomButtonRenderer : ButtonRenderer
       {
           protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
           {
               base.OnElementChanged(e);
   
               var customButton = e.NewElement as CustomButton;
   
               var thisButton = Control as Android.Widget.Button;
               thisButton.Touch += (object sender, TouchEventArgs args) =>
               {
                   if (args.Event.Action == MotionEventActions.Down)
                   {
                       customButton.OnPressed();
                   }
                   else if (args.Event.Action == MotionEventActions.Up)
                   {
                       customButton.OnReleased();
                   }
               };
           }
       }
   }
   

   For IOS

   [assembly: ExportRenderer(typeof(CustomButton), typeof(CustomButtonRenderer))]
   namespace WalkieTalkie.iOS.Renderer
   {
       public class CustomButtonRenderer : ButtonRenderer
       {
           protected override void    OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
           {
               base.OnElementChanged(e);
   
               var customButton = e.NewElement as CustomButton;
   
               var thisButton = Control as UIButton;
               thisButton.TouchDown += delegate
               {
                   customButton.OnPressed();
               };
               thisButton.TouchUpInside += delegate
               {
                   customButton.OnReleased();
               };
           }
       }
   }
   

3. Instantiate your custom button in your page

   var myButton = new CustomButton
   {
       Text = "CustomButton",
       HorizontalOptions = LayoutOptions.FillAndExpand
   };
   myButton.Pressed += (sender, args) =>
   {
       System.Diagnostics.Debug.WriteLine("Pressed");
   };
   myButton.Released += (sender, args) =>
   {
        System.Diagnostics.Debug.WriteLine("Pressed");
   };
   

Hope this help someone :)