c# - 寻找一种 Android 解决方案来阻止单击选项卡更改为新页面

Question

我的应用程序中有五个页面，如果 App.quizRunning == true 并且当前页面是 Japanese.PhrasesFrame 我需要能够停止点击任何选项卡以执行任何操作:

namespace Japanese {
    public partial class MainPage : TabbedPage {
        public MainPage() {
            InitializeComponent();
                App.cardsPage = new Cards();
                App.homePage = new HomePage();
                App.helpPage = new HelpPage();
                App.settingsPage = new SettingsPage();
                App.phrasesPage = new PhrasesFrame(this);
                Children.Add(App.navHomePage);
                Children.Add(App.navHelpPage);
                Children.Add(App.navSettingsPage);
                Children.Add(App.navCardsPage);
                Children.Add(App.navPhrasesFrame);
        }
    }
}

到目前为止，我已经有了一个 iOS 解决方案。如果有人发现这有什么问题，我将不胜感激:

using System;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
using System.Diagnostics;
using Japanese.Enums;

[assembly: ExportRenderer(typeof(TabbedPage), typeof(Japanese.iOS.TabbedPageRenderer))]
namespace Japanese.iOS {
    public class TabbedPageRenderer : TabbedRenderer {

        private MainPage _page;
        protected override void OnElementChanged(VisualElementChangedEventArgs e)
        {
            base.OnElementChanged(e);

            if (e.NewElement != null) { _page = (MainPage)e.NewElement; }
            else { _page = (MainPage)e.OldElement; }

            try {
                var tabbarController = (UITabBarController)this.ViewController;

                if (null != tabbarController) 
                    tabbarController.ViewControllerSelected += OnTabbarControllerItemSelected;

            }
            catch (Exception exception) { Console.WriteLine(exception); }
        }

        private void OnTabbarControllerItemSelected(object sender, UITabBarSelectionEventArgs eventArgs)
        {
            if (!(_page.CurrentPage is Japanese.PhrasesFrame) && App.quizRunning == true) {
                _page.CurrentPage = App.navPhrasesFrame;
            }
        }  
    }
}

现在我正在寻找 Android 解决方案，但一直找不到任何东西。

有谁知道我如何使用 Android 渲染器做到这一点？

Answer 1

不确定您为什么不尝试 CurrentPage = App.phrasesPage;

override protected void OnCurrentPageChanged() {
            var a = this.CurrentPage;
            if (Settings.mode == MO.Quiz && CurrentPage != App.phrasesPage) {
                // give the user a confirmation/alert box and
                // depending on the outcome set the variable
                // App.continueQuiz to be true or false and then 
                // go back to Japanese.PhrasesFrame page
                CurrentPage = App.phrasesPage;
            }
        }