Dismiss keyboard on button press

Xamarin Forms project

public interface IKeyboardHelper
{
    void HideKeyboard();
}  

Xamarin Forms page

DependencyService.Get<IKeyboardHelper>().HideKeyboard();

Xamarin.Android

using System;
using Xamarin.Forms;
using ProjectName;
using ProjectName.Droid;
using Xamarin.Forms.Platform.Android;
using Android.Views.InputMethods;
using Android.App;
using Android.Content;

[assembly: Xamarin.Forms.Dependency(typeof(DroidKeyboardHelper))] 
namespace ProjectName.Droid
{
    public class DroidKeyboardHelper : IKeyboardHelper
    {
        public void HideKeyboard()
        {
            var context = Android.App.Application.Context;
            var inputMethodManager = context.GetSystemService(Context.InputMethodService) as InputMethodManager;
            if (inputMethodManager != null && context is Activity)
            {
                var activity = context as Activity;
                var token = activity.CurrentFocus?.WindowToken;
                inputMethodManager.HideSoftInputFromWindow(token, HideSoftInputFlags.None);

                activity.Window.DecorView.ClearFocus();
            }
        }
    }
}

Xamarin.iOS

using System;
using Xamarin.Forms;
using ProjectName;
using ProjectName.iOS;
using UIKit;

[assembly: Dependency(typeof(iOSKeyboardHelper))]
namespace ProjectName.iOS
{
    public class iOSKeyboardHelper : IKeyboardHelper
    {
        public void HideKeyboard()
        {
            UIApplication.SharedApplication.KeyWindow.EndEditing(true);
        }
    }
}

AndroidManifest.xml

<application
   //Add this attribute
   android:windowSoftInputMode="adjustResize"
</application>