How to extend the splash screen (XAML)

發行項
08/31/2015

Display a splash screen for more time by creating an extended splash screen for your app. This extended screen imitates the splash screen shown when your app is launched, but can be customized. Whether you want to show real-time loading information or simply give your app extra time to prepare its initial UI, an extended splash screen lets you define the launch experience. To see an extended splash screen used in a complete app, see the Splash screen sample.

Using JavaScript and HTML? See How to extend the splash screen (Windows Store apps using Javascript and HTML).

Note The phrase "extended splash screen" in this topic refers to a splash screen that stays on the screen for an extended period of time. It does not mean a subclass that derives from the SplashScreen class.

Make sure your extended splash screen accurately imitates the default splash screen by following these recommendations:

Your extended splash screen page should use a 620 x 300 pixel image that is consistent with the image specified for your splash screen in your app manifest (your app's splash screen image). In Microsoft Visual Studio 2013, splash screen settings are stored in the Splash Screen section of the Visual Assets tab in your app manifest (Package.appxmanifest file).
Your extended splash screen should use a background color that is consistent with the background color specified for your splash screen in your app manifest (your app's splash screen background).
Your code should use the SplashScreen class to position your app's splash screen image at the same screen coordinates as the default splash screen.
Your code should respond to window resize events (such as when the screen is rotated or your app is moved next to another app onscreen) by using the SplashScreen class to reposition items on your extended splash screen.

Use the following steps to create an extended splash screen that effectively imitates the default splash screen.

Prerequisites

To follow the steps in this topic, you'll need Visual Studio 2013 and Windows 8.1. For downloads, see Get the tools.
This topic assumes you want to add an extended splash screen to an existing Windows Runtime app project using C#, Visual Basic, or C++. If you haven't already created an app, choose your preferred language and check out our step-by-step guidance:
- Create your first Windows Store app using C# or Visual Basic
- Create your first Windows Store app using C++
Understand the basic principles of app activation. See How to activate an app to learn about listening for and responding to Activated events.

Instructions

Step 1: Add a Blank Page item to your existing app

Open your app in Visual Studio 2013.
Press or open Project from the menu bar and click Add New Item. An Add New Item dialog box will appear.
From this dialog box, add a new Blank Page to your app. This topic names the extended splash screen page "ExtendedSplash".

Adding a Blank Page item generates two files, one for markup (ExtendedSplash.xaml) and another for code (ExtendedSplash.xaml.cs).

Step 2: Essential XAML for an extended splash screen

Follow these steps to add an image and progress control to your extended splash screen. For more guidance on designing an extended splash screen, see Guidelines and checklist for splash screens.

In your ExtendedSplash.xaml file:

Change the Background property of the default Grid element to match the background color you set for your app's splash screen in your app manifest (in the Visual Assets section of your Package.appxmanifest file). The default splash screen color is a light gray (hex value #464646). Note that this Grid element is provided by default when you create a new Blank Page. You don't have to use a Grid; it's just a convenient base for building an extended splash screen.
Add a Canvas element to the Grid. You'll use this Canvas to position your extended splash screen image.
Add an Image element to the Canvas. Use the same 600 x 320 pixel image for your extended splash screen that you chose for the default splash screen.
(Optional) Add a progress control to show users that your app is loading. This topic adds a ProgressRing, instead of a determinate or indeterminate ProgressBar. To learn how to add a ProgressBar to your app, see Adding progress controls. See Guidelines for progress controls for an overview of available controls and usage recommendations.

Add the following code to define Canvas and Image elements, as well as a ProgressRing control, in ExtendedSplash.xaml:

    <Grid Background="#464646">
        <Canvas>
            <Image x:Name="extendedSplashImage" Source="Assets/SplashScreen.png"/>
            <ProgressRing Name="splashProgressRing" IsActive="True" Width="20" HorizontalAlignment="Center"></ProgressRing>
        </Canvas>
    </Grid>

Note This code sets the width of the ProgressRing to 20 pixels. You can manually set its width to a value that works for your app, however, the control will not render at widths of less than 20 pixels.

Step 3: Essential code for an extended splash screen class

Your extended splash screen needs to respond whenever the window size (Windows only) or orientation changes. The position of the image you use must be updated so that your extended splash screen looks good no matter how the window changes.

Use these steps to define methods to correctly display your extended splash screen.

Add required namespaces

You'll need to add the following namespaces to ExtendedSplash.xaml.cs to access the SplashScreen class, Window.SizeChanged events (Windows only), and SuspensionManager class (available in the Common folder of a Blank App, Grid App, or Split App project template).
```
using Windows.ApplicationModel.Activation;
using Windows.UI.Core;
using SplashScreenExample.Common;
```
Note Replace "SplashScreenExample" in the line using SplashScreenExample.Common; with the name of your Windows Runtime app project.

Note The code in this topic restores your app to a previous session state from the extended splash screen class. This consolidates app launch tasks within ExtendedSplash.xaml.cs. Keep in mind that, if you prefer, you can restore session state directly from the OnLaunched handler in App.xaml.cs instead.
Create a partial class and declare class variables

Include the following code in ExtendedSplash.xaml.cs to create a partial class to represent an extended splash screen.
```
partial class ExtendedSplash : Page
{
    internal Rect splashImageRect; // Rect to store splash screen image coordinates.
    private SplashScreen splash; // Variable to hold the splash screen object.
    internal bool dismissed = false; // Variable to track splash screen dismissal status.
    internal Frame rootFrame;

   // Define methods and constructor
}
```
These class variables are used by several methods. The splashImageRect variable stores the coordinates where the system displayed the splash screen image for the app. The splash variable stores a SplashScreen object, and the dismissed variable tracks whether or not the splash screen that is displayed by the system has been dismissed.

Define a constructor for your class that correctly positions the image

The following code defines a constructor for the extended splash screen class that listens for window resizing events, positions the image and (optional) progress control on the extended splash screen, creates a frame for navigation, and calls an asynchronous method to restore a saved session state.

public ExtendedSplash(SplashScreen splashscreen, bool loadState)
{
    InitializeComponent();

    // Listen for window resize events to reposition the extended splash screen image accordingly.
    // This ensures that the extended splash screen formats properly in response to window resizing.
    Window.Current.SizeChanged += new WindowSizeChangedEventHandler(ExtendedSplash_OnResize);

    splash = splashscreen;
    if (splash != null)
    {
        // Register an event handler to be executed when the splash screen has been dismissed.
        splash.Dismissed += new TypedEventHandler<SplashScreen, Object>(DismissedEventHandler);

        // Retrieve the window coordinates of the splash screen image.
        splashImageRect = splash.ImageLocation;
        PositionImage();

        // If applicable, include a method for positioning a progress control.
        PositionRing();
    }

    // Create a Frame to act as the navigation context 
    rootFrame = new Frame();

    // Restore the saved session state if necessary
    RestoreStateAsync(loadState);
}

Make sure to register your Window.SizeChanged handler (ExtendedSplash_OnResize in the example) in your class constructor so that your app positions the image correctly in your extended splash screen.

Define a class method to position the image in your extended splash screen

This code demonstrates how to position the image on the extended splash screen page with the splashImageRect class variable.

void PositionImage()
{
    extendedSplashImage.SetValue(Canvas.LeftProperty, splashImageRect.X);
    extendedSplashImage.SetValue(Canvas.TopProperty, splashImageRect.Y);
    extendedSplashImage.Height = splashImageRect.Height;
    extendedSplashImage.Width = splashImageRect.Width;
}

(Optional) Define a class method to position a progress control in your extended splash screen

If you chose to add a ProgressRing to your extended splash screen, position it relative to the splash screen image. Add the following code to ExtendedSplash.xaml.cs to center the ProgressRing 32 pixels below the image.
```
void PositionRing()
{
    splashProgressRing.SetValue(Canvas.LeftProperty, splashImageRect.X + (splashImageRect.Width*0.5) - (splashProgressRing.Width*0.5));
    splashProgressRing.SetValue(Canvas.TopProperty, (splashImageRect.Y + splashImageRect.Height + splashImageRect.Height*0.1));
}
```

Inside the class, define a handler for the Dismissed event

In ExtendedSplash.xaml.cs, respond when the SplashScreen.Dismissed event occurs by setting the dismissed class variable to true. If your app has setup operations, add them to this event handler.

// Include code to be executed when the system has transitioned from the splash screen to the extended splash screen (application's first view).
void DismissedEventHandler(SplashScreen sender, object e)
{
    dismissed = true;

    // Complete app setup operations here...
}

After app setup is complete, navigate away from your extended splash screen. The following code defines a method called DismissExtendedSplash that navigates to the MainPage defined in your app's MainPage.xaml file.

void DismissExtendedSplash()
{
    // Navigate to mainpage
    rootFrame.Navigate(typeof(MainPage));
    // Place the frame in the current Window
    Window.Current.Content = rootFrame;
}

Inside the class, define a handler for Window.SizeChanged events

Prepare your extended splash screen to reposition its elements if a user resizes the window. This code responds when a Window.SizeChanged event occurs by capturing the new coordinates and repositioning the image. If you added a progress control to your extended splash screen, reposition it inside this event handler as well.
```
void ExtendedSplash_OnResize(Object sender, WindowSizeChangedEventArgs e)
{
    // Safely update the extended splash screen image coordinates. This function will be executed when a user resizes the window.
    if (splash != null)
    {
        // Update the coordinates of the splash screen image.
        splashImageRect = splash.ImageLocation;
        PositionImage();

        // If applicable, include a method for positioning a progress control.
        // PositionRing();
    }
}
```
Note Before you try to get the image location make sure the class variable (splash) contains a valid SplashScreen object, as shown in the example.
Add a class method to restore a saved session state

The code you added to the OnLaunched method in Step 4: Modify the launch activation handler causes your app to display an extended splash screen when it launches. To consolidate all methods related to app launch in your extended splash screen class, add the following asynchronous method to your ExtendedSplash.xaml.cs file.
```
async void RestoreStateAsync(bool loadState)
{
    if (loadState)
        await SuspensionManager.RestoreAsync();
}
```
When you modify the launch activation handler in App.xaml.cs, you'll also set loadstate to true if the previous ApplicationExecutionState of your app was Terminated. If so, the RestoreStateAsync method calls SuspensionManager to restore the app to its previous state. For an overview of app launch, suspension, and termination, see App lifecycle.

Step 4: Modify the launch activation handler

When your app is launched, the system passes splash screen information to the app's launch activation event handler. You can use this information to correctly position the image on your extended splash screen page. You can get this splash screen information from the activation event arguments that are passed to your app's OnLaunched handler (see the args variable in the following code).

If you have not already overridden the OnLaunched handler for your app, see How to activate an app to learn how to handle activation events.

In App.xaml.cs, add the following code to create and display an extended splash screen.

protected override void OnLaunched(LaunchActivatedEventArgs args)
{
    if (args.PreviousExecutionState != ApplicationExecutionState.Running)
    {
        bool loadState = (args.PreviousExecutionState == ApplicationExecutionState.Terminated);
        ExtendedSplash extendedSplash = new ExtendedSplash(args.SplashScreen, loadState);
        Window.Current.Content = extendedSplash;
    }

    Window.Current.Activate();
}

Step 5: Complete code

Note The following code slightly differs from the snippets shown in the previous steps.

ExtendedSplash.xaml includes a DismissSplash button. When this button is clicked, an event handler, DismissSplashButton_Click, calls the DismissExtendedSplash method. In your app, call DismissExtendedSplash when your app is done loading resources or initializing its UI.
This app also uses a Windows Runtime app project template, which uses Frame navigation. As a result, in App.xaml.cs, the launch activation handler (OnLaunched) defines a rootFrame and uses it to set the content of the app window.

ExtendedSplash.xaml: This example includes a DismissSplash button because it doesn't have app resources to load. In your app, dismiss the extended splash screen automatically when your app is done loading resources or preparing its initial UI.

<Page
    x:Class="SplashScreenExample.ExtendedSplash"
    xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:SplashScreenExample"
    xmlns:d="https://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="https://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="#464646">
        <Canvas>
            <Image x:Name="extendedSplashImage" Source="Assets/SplashScreen.png"/>
            <ProgressRing Name="splashProgressRing" IsActive="True" Width="20" HorizontalAlignment="Center"/>
        </Canvas>
        <StackPanel HorizontalAlignment="Center" VerticalAlignment="Bottom">
            <Button x:Name="DismissSplash" Content="Dismiss extended splash screen" HorizontalAlignment="Center" Click="DismissSplashButton_Click" />
        </StackPanel>
    </Grid>
</Page>

ExtendedSplash.xaml.cs: Note that the DismissExtendedSplash method is called from the click event handler for the DismissSplash button. In your app, you won't need a DismissSplash button. Instead, call DismissExtendedSplash when your app is done loading resources and you want to navigate to its main page.

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.UI.Xaml.Navigation;

using Windows.ApplicationModel.Activation;
using SplashScreenExample.Common;
using Windows.UI.Core;

// The Blank Page item template is documented at https://go.microsoft.com/fwlink/p/?LinkID=234238

namespace SplashScreenExample
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    partial class ExtendedSplash : Page
    {
        internal Rect splashImageRect; // Rect to store splash screen image coordinates.
        private SplashScreen splash; // Variable to hold the splash screen object.
        internal bool dismissed = false; // Variable to track splash screen dismissal status.
        internal Frame rootFrame;

        public ExtendedSplash(SplashScreen splashscreen, bool loadState)
        {
            InitializeComponent();

            // Listen for window resize events to reposition the extended splash screen image accordingly.
            // This is important to ensure that the extended splash screen is formatted properly in response to snapping, unsnapping, rotation, etc...
            Window.Current.SizeChanged += new WindowSizeChangedEventHandler(ExtendedSplash_OnResize);

            splash = splashscreen;

            if (splash != null)
            {
                // Register an event handler to be executed when the splash screen has been dismissed.
                splash.Dismissed += new TypedEventHandler<SplashScreen, Object>(DismissedEventHandler);

                // Retrieve the window coordinates of the splash screen image.
                splashImageRect = splash.ImageLocation;
                PositionImage();

                // Optional: Add a progress ring to your splash screen to show users that content is loading
                PositionRing();
            }

            // Create a Frame to act as the navigation context
            rootFrame = new Frame();

            // Restore the saved session state if necessary
            RestoreStateAsync(loadState);
        }

        async void RestoreStateAsync(bool loadState)
        {
            if (loadState)
                await SuspensionManager.RestoreAsync();
        }

        // Position the extended splash screen image in the same location as the system splash screen image.
        void PositionImage()
        {
            extendedSplashImage.SetValue(Canvas.LeftProperty, splashImageRect.X);
            extendedSplashImage.SetValue(Canvas.TopProperty, splashImageRect.Y);
            extendedSplashImage.Height = splashImageRect.Height;
            extendedSplashImage.Width = splashImageRect.Width;

        }

        void PositionRing()
        {
            splashProgressRing.SetValue(Canvas.LeftProperty, splashImageRect.X + (splashImageRect.Width*0.5) - (splashProgressRing.Width*0.5));
            splashProgressRing.SetValue(Canvas.TopProperty, (splashImageRect.Y + splashImageRect.Height + splashImageRect.Height*0.1));
        }

        void ExtendedSplash_OnResize(Object sender, WindowSizeChangedEventArgs e)
        {
            // Safely update the extended splash screen image coordinates. This function will be fired in response to snapping, unsnapping, rotation, etc...
            if (splash != null)
            {
                // Update the coordinates of the splash screen image.
                splashImageRect = splash.ImageLocation;
                PositionImage();
                PositionRing();
            }
        }

        // Include code to be executed when the system has transitioned from the splash screen to the extended splash screen (application's first view).
        void DismissedEventHandler(SplashScreen sender, object e)
        {
            dismissed = true;

            // Complete app setup operations here...
        }

        void DismissExtendedSplash()
        {
            // Navigate to mainpage
            rootFrame.Navigate(typeof(MainPage));
            // Place the frame in the current Window
            Window.Current.Content = rootFrame;
        }

        void DismissSplashButton_Click(object sender, RoutedEventArgs e)
        {
            DismissExtendedSplash();
        }
    }
}

App.xaml.cs: This project was created using the Windows Runtime app Blank App (XAML) project template in Visual Studio 2013. Both the OnNavigationFailed and OnSuspending event handlers are automatically generated and don't need to be changed to implement an extended splash screen. This topic only modifies OnLaunched.

If you didn't use a project template for your app, see Step 4: Modify the launch activation handler for an example of a modified OnLaunched handler that doesn't use Frame navigation.

using SplashScreenExample.Common;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
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.UI.Xaml.Navigation;

// The Blank Application template is documented at https://go.microsoft.com/fwlink/p/?LinkID=234227

namespace SplashScreenExample
{
    /// <summary>
    /// Provides application-specific behavior to supplement the default Application class.
    /// </summary>
    sealed partial class App : Application
    {
        /// <summary>
        /// Initializes the singleton application object.  This is the first line of authored code
        /// executed, and as such is the logical equivalent of main() or WinMain().
        /// </summary>
        public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;
        }

        /// <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 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();
                // Set the default language
                rootFrame.Language = Windows.Globalization.ApplicationLanguages.Languages[0];

                rootFrame.NavigationFailed += OnNavigationFailed;

                //  Display an extended splash screen if app was not previously running.
                if (e.PreviousExecutionState != ApplicationExecutionState.Running)
                {
                    bool loadState = (e.PreviousExecutionState == ApplicationExecutionState.Terminated);
                    ExtendedSplash extendedSplash = new ExtendedSplash(e.SplashScreen, loadState);
                    rootFrame.Content = extendedSplash;
                    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
                rootFrame.Navigate(typeof(MainPage), e.Arguments);
            }
            // Ensure the current window is active
            Window.Current.Activate();
        }

        /// <summary>
        /// Invoked when Navigation to a certain page fails
        /// </summary>
        /// <param name="sender">The Frame which failed navigation</param>
        /// <param name="e">Details about the navigation failure</param>
        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
        }

        /// <summary>
        /// Invoked when application execution is being suspended.  Application state is saved
        /// without knowing whether the application will be terminated or resumed with the contents
        /// of memory still intact.
        /// </summary>
        /// <param name="sender">The source of the suspend request.</param>
        /// <param name="e">Details about the suspend request.</param>
        async private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            await SuspensionManager.SaveAsync();
            deferral.Complete();
        }
    }
}

Remarks

Tip If you followed these instructions and you notice a flicker during the transition to your extended splash screen, see the Troubleshooting section in Guidelines and checklist for splash screens for help.

Guidelines and checklist for splash screens

How to activate an app

App lifecycle (Overview)

Splash screen sample

How to extend the splash screen (Windows Store apps using Javascript and HTML)

Reference

Windows.ApplicationModel.Activation namespace

Windows.ApplicationModel.Activation.SplashScreen class

Windows.ApplicationModel.Activation.SplashScreen.ImageLocation property

Windows.ApplicationModel.Core.CoreApplicationView.Activated event