private async void btn_Clicked(object sender, EventArgs e)
        {
            AnotherPage      newPage = new AnotherPage();
            DataPassingClass obj     = (DataPassingClass)this.BindingContext;

            obj.Index++;
            newPage.BindingContext = obj;
            await Navigation.PushAsync(newPage);
        }
        public App()
        {
            InitializeComponent();
            //Uncomment the below to demo BindingContext data passing to a page

            AnotherPage anotherPage = new AnotherPage();

            anotherPage.BindingContext = new DataPassingClass
            {
                Index = 0
            };

            MainPage = new NavigationPage(anotherPage);
            //MainPage = new AnotherPage();

            //Demo Navigaton page using MainPage
            //MainPage = new NavigationPage(new MainPage());
        }