SuspensionManager.RestoreAsync C# (CSharp) Method

    static async public Task RestoreAsync()
    {
        // Get the input stream for the SessionState file.
        try
        {
            StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync(filename);
            if (file == null) return;
            using (IInputStream inStream = await file.OpenSequentialReadAsync())
            {
                // Deserialize the Session State.
                DataContractSerializer serializer = new DataContractSerializer(typeof(Dictionary<string, object>), knownTypes_);
                sessionState_ = (Dictionary<string, object>)serializer.ReadObject(inStream.AsStreamForRead());
            }
        }
        catch (Exception)
        {
            // Restoring state is best-effort.  If it fails, the app will just come up with a new session.
        }
    }
}

        /// <summary>
        /// Invoked when the application is launched normally by the end user.  Other entry points
        /// will be used such as when the application is launched to open a specific file.
        /// </summary>
        /// <param name="e">Details about the launch request and process.</param>
        protected override async void OnLaunched(LaunchActivatedEventArgs e)
        {
#if DEBUG
            if (System.Diagnostics.Debugger.IsAttached)
            {
                this.DebugSettings.EnableFrameRateCounter = true;
            }
#endif

            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();
                //Associate the frame with a SuspensionManager key
                SuspensionManager.RegisterFrame(rootFrame, "AppFrame");

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    // Restore the saved session state only when appropriate
                    try
                    {
                        await SuspensionManager.RestoreAsync();
                    }
                    catch (SuspensionManagerException)
                    {
                        //Something went wrong restoring state.
                        //Assume there is no state and continue
                    }
                }

                // Place the frame in the current Window
                Window.Current.Content = rootFrame;
            }
            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
                if (!rootFrame.Navigate(typeof(HubPage)))
                {
                    throw new Exception("Failed to create initial page");
                }
            }
            // Ensure the current window is active
            Window.Current.Activate();
        }