UWP根框架与页面框架

Question

这是典型的App.xaml.cs代码

protected override void OnLaunched(LaunchActivatedEventArgs e)
    {
#if DEBUG
        if (System.Diagnostics.Debugger.IsAttached)
        {
            //this.DebugSettings.EnableFrameRateCounter = true;
        }
#endif
        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 (e.PrelaunchActivated == false)
        {
            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(SignInPage), e.Arguments);
            }
            // Ensure the current window is active
            Window.Current.Activate();
        }
    }

当rootFrame.Navigate(typeof(SignInPage), e.Arguments); 调用， SignInPage被创建。 在SignInPage.xaml.cs ，可能会有类似以下代码： this.Frame.Navigate(typeof(FramePage)); 。 是来自this.Frame.的Frame this.Frame. 和rootFrame吗？ 如果是的话，那么在何时何地从App.xaml.cs中为Page类分配根框架？

Answer 1

是的，这是同一个Frame对象，因为Page引用了控制其内容的框架。 换句话说，导航到页面的Frame 。

帧

获取页面内容的控制框架。

资料来源： docs.microsoft.com

此属性在导航时自动设置，并且首先在OnNavigatedTo方法的Page对象中OnNavigatedTo 。