Windows 10 UAP后退按钮

Question

如何处理windows mobile 10的后退按钮和windows 10平板电脑模式的后退按钮？我到处都在找，但找不到任何例子。

Answer 1

本主题是Guide to Universal Windows Platform apps中使用的示例之一。我强烈建议在开始使用通用应用程序时阅读这篇文章。

对于页眉上的按钮，使用Windows.UI.Core.SystemNavigationManager并设置AppViewBackButtonVisibility属性以显示或隐藏该按钮，并处理BackRequested事件以执行导航。

Windows.UI.Core.SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
Windows.UI.Core.SystemNavigationManager.GetForCurrentView().BackRequested += (s,a) =>
{
    Debug.WriteLine("BackRequested");
    if (Frame.CanGoBack)
    {
        Frame.GoBack();
        a.Handled = true;
    }
}

您可以像在Windows phone8.1中一样连接硬件back按钮，但您应该检查PhoneContract (或单个类和方法)以确保它在那里：

if (ApiInformation.IsApiContractPresent ("Windows.Phone.PhoneContract", 1, 0)) {  
    Windows.Phone.UI.Input.HardwareButtons.BackPressed += (s, a) =>
    {
        Debug.WriteLine("BackPressed");
        if (Frame.CanGoBack)
        {
            Frame.GoBack();
            a.Handled = true;
        }
    };
}

Answer 2

将以下代码添加到您的App.xaml.cs中，它将处理桌面、平板电脑和移动设备上的导航(我在移动模拟器上对其进行了测试)，以便更好地突出显示差异和解释(由JEFF PROSISE提供的Handling The Back Button In Windows 10 UWP Apps)

sealed partial class App : Application
{

    public App()
    {
        this.InitializeComponent();
        this.Suspending += OnSuspending;
    }

    protected override void OnLaunched(LaunchActivatedEventArgs e)
    {
        Frame rootFrame = Window.Current.Content as Frame;

        // Do not repeat app initialization when the Window already has content,
        // just ensure that the window is active
        if (rootFrame == null)
        {
            // Create a Frame to act as the navigation context and navigate to the first page
            rootFrame = new Frame();

            rootFrame.NavigationFailed += OnNavigationFailed;
            rootFrame.Navigated += OnNavigated;

            if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
            {
                // TODO: Load state from previously suspended application
            }

            // Place the frame in the current Window
            Window.Current.Content = rootFrame;

            // Register a handler for BackRequested events and set the
            // visibility of the Back button
            SystemNavigationManager.GetForCurrentView().BackRequested += OnBackRequested;

            SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility =
                rootFrame.CanGoBack  ?
                AppViewBackButtonVisibility.Visible :
                AppViewBackButtonVisibility.Collapsed;
        }

        if (rootFrame.Content == null)
        {
            // When the navigation stack isn't restored navigate to the first page,
            // configuring the new page by passing required information as a navigation
            // parameter
            rootFrame.Navigate(typeof(MainPage), e.Arguments);
        }

        // Ensure the current window is active
        Window.Current.Activate();
    }

    void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
    {
        throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
    }

    private void OnNavigated(object sender, NavigationEventArgs e)
    {
        // Each time a navigation event occurs, update the Back button's visibility
        SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility =
            ((Frame)sender).CanGoBack ?
            AppViewBackButtonVisibility.Visible :
            AppViewBackButtonVisibility.Collapsed;
    }

    private void OnSuspending(object sender, SuspendingEventArgs e)
    {
        var deferral = e.SuspendingOperation.GetDeferral();
        // TODO: Save application state and stop any background activity
        deferral.Complete();
    }

    private void OnBackRequested(object sender, BackRequestedEventArgs e)
    {
        Frame rootFrame = Window.Current.Content as Frame;

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