Confirmation Dialog on back button press event Xamarin.Forms

Question

I am stuck at one point in Xamarin.Forms application

On Back button press simply I want to ask user to confirm whether he really wants to exit or not, \"OnBackButton

Answer 1

 private async void OnDelete(object sender, EventArgs e)
        {
            var result = await this.DisplayAlert("Alert!", "Do you really want to exit?", "Yes", "No");
            if (result)
            {

                var menuitem = sender as MenuItem;
                string name = menuitem.BindingContext as string;

                lielements.Remove(name);
            }
            else
            {


            }

        }