ToastMessageService.cs

ToastMessageService.cs

[assembly: Xamarin.Forms.Dependency(typeof(ToastMessageService))]
namespace ToastTestXamarin.Droid
{
    public class ToastMessageService : IToastMessageService
    {
        public void ShowToastMessage(string message)
        {
           Toast.MakeText(Android.App.Application.Context, message, ToastLength.Long).Show();
        }
    }
}