Xamarin.Forms 中默认是不实现这两个功能的，这就需要你在 Renderer 中自己去实现，下面是关于如何在 Xamarin.Android 中实现这个功能的代码：

Forms 部分代码

public interface IMyButtonController : IViewController{    void SendTouched();    void SendLongClicked();    void SendReleased();}

public class MyButton : Xamarin.Forms.Button, IMyButtonController{    public event EventHandler Touched;    void IMyButtonController.SendTouched()    {        Touched?.Invoke(this, EventArgs.Empty);    }    public event EventHandler LongClicked;    void IMyButtonController.SendLongClicked()    {        LongClicked?.Invoke(this, EventArgs.Empty);    }    public event EventHandler Released;    void IMyButtonController.SendReleased()    {        Released?.Invoke(this, EventArgs.Empty);    }}

在 Xamarin.Android 中的 Renderer：

[assembly: ExportRenderer(typeof(MyButton), typeof(MyButtonRenderer))]namespace ProjectNameSpace.Droid{    public class MyButtonRenderer : Xamarin.Forms.Platform.Android.ButtonRenderer    {        protected override void OnElementChanged(ElementChangedEventArgs
    
      e)        {            base.OnElementChanged(e);            if (e.NewElement != null)            {                if (Control != null)                {                    Control.SetOnTouchListener(ButtonTouchListener.Instance.Value);                    Control.LongClickable = true;                    Control.SetOnLongClickListener(ButtonLongClickListener.Instance.Value);                }            }        }        protected override void Dispose(bool disposing)        {            if (disposing)            {                if (Control != null)                {                    Control.SetOnTouchListener(null);                    Control.SetOnLongClickListener(null);                }            }            base.Dispose(disposing);        }        private class ButtonTouchListener : Java.Lang.Object, Android.Views.View.IOnTouchListener        {            public static readonly Lazy
     
       Instance = new Lazy
      
       (() => new ButtonTouchListener());            public bool OnTouch(Android.Views.View v, Android.Views.MotionEvent e)            {                var renderer = v.Tag as ButtonRenderer;                if (renderer != null)                {                    var buttonController = renderer.Element as IMyButtonController;                    if (e.Action == Android.Views.MotionEventActions.Down)                    {                        buttonController?.SendTouched();                    }                    else if (e.Action == Android.Views.MotionEventActions.Up)                    {                        buttonController?.SendReleased();                    }                }                return false;            }        }        private class ButtonLongClickListener : Java.Lang.Object, Android.Views.View.IOnLongClickListener        {            public static readonly Lazy
       
         Instance = new Lazy
        
         (() => new ButtonLongClickListener());            public bool OnLongClick(Android.Views.View v)            {                var renderer = v.Tag as ButtonRenderer;                ((IMyButtonController)renderer?.Element)?.SendLongClicked();                return true;            }        }    }}