c# - 如何在 Windows Phone 中存储应用程序状态

Question

我有一个应用程序，当我打开它一次时它工作得很好，但现在的问题是如果用户点击 Windows 主页键它退出应用程序并将我的应用程序移到后台。现在，如果用户长按返回键并打开我的应用程序，它会返回到用户按下主页键的同一页面。但是如果用户点击应用程序图标，我的应用程序会从头开始，这是我不想要的。请帮我。谢谢

告诉我应该把代码放在哪里，这样我才能得到想要的结果。

我的 App.xaml 如下: =================

namespace MyProj
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : Application
    {

        // Easy access to the root frame
        public PhoneApplicationFrame RootFrame
        {
            get;
            private set;
        }

        // Constructor
        public App()
        {
            // Global handler for uncaught exceptions. 
            UnhandledException += Application_UnhandledException;

            // Standard Silverlight initialization
            InitializeComponent();

            // Phone-specific initialization
            InitializePhoneApplication();


            // Show graphics profiling information while debugging.
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // Display the current frame rate counters.
                Application.Current.Host.Settings.EnableFrameRateCounter = true;

                // Show the areas of the app that are being redrawn in each frame.
                //Application.Current.Host.Settings.EnableRedrawRegions = true;

                // Enable non-production analysis visualization mode, 
                // which shows areas of a page that are handed off to GPU with a colored overlay.
                //Application.Current.Host.Settings.EnableCacheVisualization = true;

                // Disable the application idle detection by setting the UserIdleDetectionMode property of the
                // application's PhoneApplicationService object to Disabled.
                // Caution:- Use this under debug mode only. Application that disable user idle detection will continue to run
                // and consume battery power when the user is not using the phone.
                PhoneApplicationService.Current.UserIdleDetectionMode = IdleDetectionMode.Disabled;
            }

        }

        // Code to execute when the application is launching (eg, from Start)
        // This code will not execute when the application is reactivated
        private void Application_Launching(object sender, LaunchingEventArgs e)
        {

        }

        // Code to execute when the application is activated (brought to foreground)
        // This code will not execute when the application is first launched
        private void Application_Activated(object sender, ActivatedEventArgs e)
        {
            // Restart session

        }

        // Code to execute when the application is deactivated (sent to background)
        // This code will not execute when the application is closing
        private void Application_Deactivated(object sender, DeactivatedEventArgs e)
        {
        }

        // Code to execute when the application is closing (eg, user hit Back)
        // This code will not execute when the application is deactivated
        private void Application_Closing(object sender, ClosingEventArgs e)
        {
            ViewModelLocator.Cleanup();
        }

        // Code to execute if a navigation fails
        private void RootFrame_NavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // A navigation has failed; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
        }

        // Code to execute on Unhandled Exceptions
        private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // An unhandled exception has occurred; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
        }

        #region Phone application initialization

        // Avoid double-initialization
        private bool phoneApplicationInitialized = false;

        // Do not add any additional code to this method
        private void InitializePhoneApplication()
        {
            if (phoneApplicationInitialized)
                return;

            // Create the frame but don't set it as RootVisual yet; this allows the splash
            // screen to remain active until the application is ready to render.
            //RootFrame = new PhoneApplicationFrame();
            RootFrame = new TransitionFrame();
            RootFrame.Navigated += CompleteInitializePhoneApplication;

            // Handle navigation failures
            RootFrame.NavigationFailed += RootFrame_NavigationFailed;

            // Ensure we don't initialize again
            phoneApplicationInitialized = true;
        }

        // Do not add any additional code to this method
        private void CompleteInitializePhoneApplication(object sender, NavigationEventArgs e)
        {
            // Set the root visual to allow the application to render
            if (RootVisual != RootFrame)
                RootVisual = RootFrame;

            // Remove this handler since it is no longer needed
            RootFrame.Navigated -= CompleteInitializePhoneApplication;
        }

        #endregion
    }
}

Answer 1

您需要实现逻辑删除功能。刚刚阅读
App activation and deactivation for Windows Phone