demo-xf-app-1a/MobileApp1/Helpers/ContentPageHelper.cs

using Xamarin.Forms;

namespace MobileApp1.Views
{
    public class ContentPageHelper
    {

        public static App GetApp(ContentPage view)
        {
            if (view == null) return null;

            Element item = view.Parent;

            while (true)
            {
                if (item == null) break;
                if (item is App) break;

                item = item.Parent;
            }

            return (item as App);
        }

        public static Application GetApplication(ContentPage view)
        {
            if (view == null) return null;

            Element item = view.Parent;

            while (true)
            {
                if (item == null) break;
                if (item is Application) break;

                item = item.Parent;
            }

            return (item as Application);
        }

        public static void SetMainPage(ContentPage view, Page page)
        {
            if (view == null) return;
            if (view.Parent == null) return;
            if (page == null) return;

            Application rs = GetApplication(view);
            if (rs == null)
            {
                return;
            }

            //rs.MainPage = new NavigationPage(new PasswordResetPage());
            rs.MainPage = page;
        }

        public static async void PushMainPageNavigation(ContentPage view, Page page)
        {
            if (view == null) return;
            if (view.Parent == null) return;
            if (page == null) return;

            Application rs = GetApplication(view);
            if (rs == null)
            {
                return;
            }

            await rs?.MainPage.Navigation.PushAsync(page);
        }

    }
}