Windows Phone后退按钮关闭应用程序，而不是返回页面

Question

Working on a basic Windows Universal app and currently have the issue where upon pressing back on the details page of my lists it doesn't take me back to the main page but instead closes the app entirely.

MainPage.xaml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.Phone.UI;
using Windows.UI.Xaml.Navigation;

namespace MoreUniversalAppWork
{
    public sealed partial class MainPage : Page
    {
        public QuoteReader qr = new QuoteReader();
        public MainPage()
        {
            this.InitializeComponent();

            this.NavigationCacheMode = NavigationCacheMode.Required;
            qr.DownloadQuotes();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {

        }
        private void Hardware_Back(object sender, Windows.Phone.UI.Input.BackPressedEventArgs e)
        {
            if (Frame.Content is ViewQuote)
            {
                Frame.Navigate(typeof(MainPage));
                e.Handled = true;
            }
        }
        private void LoadQuotes(object sender, RoutedEventArgs e)
        {
            FillList();
        }
        private void FillList()
        {
            // Downloads the JSON file with the quotes and filles List //
            qr.DownloadQuotes();
            var quotes = qr.quotes_dictionary();
            list_quotes.Items.Clear();
            foreach (var q in quotes)
            {
                list_quotes.Items.Add(q.Value);
            }
            if (list_quotes.Items.Count > 0)
            {
                list_quotes.ScrollIntoView(list_quotes.Items[0]);
            }
        }
        private void ViewQuote(object sender, SelectionChangedEventArgs e)
        {
            // Upon clicking quote in list, details page is opened //
            Frame.Navigate(typeof(ViewQuote), list_quotes.SelectedValue);
        }
    }
}

ViewQuote.xaml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.ComponentModel;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Phone.UI.Input;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkID=390556

namespace MoreUniversalAppWork
{
    public sealed partial class ViewQuote : Page
    {
        string quote;
        public ViewQuote()
        {
            this.InitializeComponent();
        }
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            quote = e.Parameter as string;
            quote_display.Text = quote;
        }
    }
}

Answer 1

This is normal in Windows Phone 8.1. You may want to have a workaround in App.xaml.cs file.

public App()
{
    this.InitializeComponent();   
    HardwareButtons.BackPressed += HardwareButtons_BackPressed;        
}

void HardwareButtons_BackPressed(object sender, BackPressedEventArgs e)
{
    Frame rootFrame = Window.Current.Content as Frame;

    if (rootFrame != null && rootFrame.CanGoBack)
    {
        e.Handled = true;
        rootFrame.GoBack();
    }
}

WP8.1 back button quits the app