Part 2 Complete code (Windows Store apps using C#/VB and XAML)

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This topic provides the complete code sample used in the tutorial Part 2: Manage app lifecycle and state.

This topic contains these sections:

Download location

This sample is not available for download.

Technologies

Programming languagesC#, Visual Basic .NET
Programming modelsWindows Runtime

Requirements

Minimum supported clientWindows 8
Minimum supported serverWindows Server 2012
Minimum required SDKMicrosoft Visual Studio Express 2012 for Windows 8

View the code ()

App.xaml

App.xaml is unchanged from Part 1.

App.xaml.cs/vb


using System;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

// The Blank Application template is documented at http://go.microsoft.com/fwlink/?LinkId=234227

namespace HelloWorld
{
    /// <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 when the application is launched to open a specific file, to display
        /// search results, and so forth.
        /// </summary>
        /// <param name="args">Details about the launch request and process.</param>
        protected async override void OnLaunched(LaunchActivatedEventArgs args)
        {
            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();
                HelloWorld.Common.SuspensionManager.RegisterFrame(rootFrame, "appFrame");

                if (args.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: Load state from previously suspended application
                    await HelloWorld.Common.SuspensionManager.RestoreAsync();
                }

                // 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(MainPage), args.Arguments))
                {
                    throw new Exception("Failed to create initial page");
                }
            }
            // Ensure the current window is active
            Window.Current.Activate();
        }

        /// <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>
        private async void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            //TODO: Save application state and stop any background activity
            await HelloWorld.Common.SuspensionManager.SaveAsync();
            deferral.Complete();
        }
    }
}


MainPage.xaml


<common:LayoutAwarePage
    x:Name="pageRoot"
    x:Class="HelloWorld.MainPage"
    DataContext="{Binding DefaultViewModel, RelativeSource={RelativeSource Self}}"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:HelloWorld"
    xmlns:common="using:HelloWorld.Common"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Page.Resources>
        <!-- TODO: Delete this line if the key AppName is declared in App.xaml -->
        <x:String x:Key="AppName">Hello, world!</x:String>
    </Page.Resources>

    <!--
        This grid acts as a root panel for the page that defines two rows:
        * Row 0 contains the back button and page title
        * Row 1 contains the rest of the page layout
    -->
    <Grid Style="{StaticResource LayoutRootStyle}">
        <Grid.RowDefinitions>
            <RowDefinition Height="140"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!-- Back button and page title -->
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>
            <Button x:Name="backButton" Click="GoBack" 
                    IsEnabled="{Binding Frame.CanGoBack, ElementName=pageRoot}" 
                    Style="{StaticResource BackButtonStyle}"/>
            <TextBlock x:Name="pageTitle" Grid.Column="1" 
                       Text="{StaticResource AppName}" Style="{StaticResource PageHeaderTextStyle}"/>
        </Grid>
        
        <!-- Controls added in PART 1. -->
        <StackPanel Grid.Row="1" Margin="120,30,0,0">
            <TextBlock Text="What's your name?" Style="{StaticResource BasicTextStyle}"/>
            <StackPanel Orientation="Horizontal" Margin="0,20,0,20">
                <TextBox x:Name="nameInput" Width="300" HorizontalAlignment="Left"
                         TextChanged="NameInput_TextChanged"/>
                <Button Content="Say &quot;Hello&quot;" Click="Button_Click"/>
            </StackPanel>
            <TextBlock x:Name="greetingOutput" Style="{StaticResource BigGreenTextStyle}"/>
        </StackPanel>
        <!-- End -->

        <VisualStateManager.VisualStateGroups>

            <!-- Visual states reflect the application's view state -->
            <VisualStateGroup x:Name="ApplicationViewStates">
                <VisualState x:Name="FullScreenLandscape"/>
                <VisualState x:Name="Filled"/>

                <!-- The entire page respects the narrower 100-pixel margin convention for portrait -->
                <VisualState x:Name="FullScreenPortrait">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="backButton" 
                                                       Storyboard.TargetProperty="Style">
                            <DiscreteObjectKeyFrame KeyTime="0" 
                                                    Value="{StaticResource PortraitBackButtonStyle}"/>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>

                <!-- The back button and title have different styles when snapped -->
                <VisualState x:Name="Snapped">
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="backButton" 
                                                       Storyboard.TargetProperty="Style">
                            <DiscreteObjectKeyFrame KeyTime="0" 
                                                    Value="{StaticResource SnappedBackButtonStyle}"/>
                        </ObjectAnimationUsingKeyFrames>
                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="pageTitle" 
                                                       Storyboard.TargetProperty="Style">
                            <DiscreteObjectKeyFrame KeyTime="0" 
                                                    Value="{StaticResource SnappedPageHeaderTextStyle}"/>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </VisualState>
            </VisualStateGroup>
        </VisualStateManager.VisualStateGroups>
    </Grid>
</common:LayoutAwarePage>


MainPage.xaml.cs/vb


using System;
using System.Collections.Generic;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

// The Basic Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234237

namespace HelloWorld
{
    /// <summary>
    /// A basic page that provides characteristics common to most applications.
    /// </summary>
    public sealed partial class MainPage : HelloWorld.Common.LayoutAwarePage
    {
        public MainPage()
        {
            this.InitializeComponent();
        }

        /// <summary>
        /// Populates the page with content passed during navigation.  Any saved state is also
        /// provided when recreating a page from a prior session.
        /// </summary>
        /// <param name="navigationParameter">The parameter value passed to
        /// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested.
        /// </param>
        /// <param name="pageState">A dictionary of state preserved by this page during an earlier
        /// session.  This will be null the first time a page is visited.</param>
        protected override void LoadState(Object navigationParameter, Dictionary<String, Object> pageState)
        {
            // Restore values stored in session state.
            if (pageState != null && pageState.ContainsKey("greetingOutputText"))
            {
                greetingOutput.Text = pageState["greetingOutputText"].ToString();
            }

            // Restore values stored in app data.
            Windows.Storage.ApplicationDataContainer roamingSettings =
                Windows.Storage.ApplicationData.Current.RoamingSettings;
            if (roamingSettings.Values.ContainsKey("userName"))
            {
                nameInput.Text = roamingSettings.Values["userName"].ToString();
            }
        }

        /// <summary>
        /// Preserves state associated with this page in case the application is suspended or the
        /// page is discarded from the navigation cache.  Values must conform to the serialization
        /// requirements of <see cref="SuspensionManager.SessionState"/>.
        /// </summary>
        /// <param name="pageState">An empty dictionary to be populated with serializable state.</param>
        protected override void SaveState(Dictionary<String, Object> pageState)
        {
            pageState["greetingOutputText"] = greetingOutput.Text;

            // The user name is already saved, so you don't need to save it here.
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            greetingOutput.Text = "Hello, " + nameInput.Text + "!";
        }

        private void NameInput_TextChanged(object sender, TextChangedEventArgs e)
        {
            Windows.Storage.ApplicationDataContainer roamingSettings =
                Windows.Storage.ApplicationData.Current.RoamingSettings;
            roamingSettings.Values["userName"] = nameInput.Text;
        }
    }
}


 

 

Build date: 3/11/2013

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