Part 4 Complete code (Windows Store apps using C#/VB and XAML)
[ This article is for Windows 8.x and Windows Phone 8.x developers writing Windows Runtime apps. If you’re developing for Windows 10, see the latest documentation ]
This topic provides the complete code sample used in the tutorial Part 4: File access and pickers.
Important This tutorial is intended for use with Microsoft Visual Studio 2013 and Windows 8.1. Parts of it will not work correctly with Microsoft Visual Studio 2012 and Windows 8.
This topic contains these sections:
- Technologies
- Requirements
- View the code (XAML)
Download location
This sample is not available for download.
Technologies
| Programming languages | C#, Visual Basic .NET |
| Programming models | Windows Runtime |
Requirements
| Minimum supported client | Windows 8.1 |
| Minimum supported server | Windows Server 2012 R2 |
| Minimum required SDK | Microsoft Visual Studio Express 2012 for Windows 8 |
View the code (XAML)
App.xaml
App.xaml contains only generated code.
App.xaml.cs/vb
App.xaml.cs/vb is unchanged from Part 2.
MainPage.xaml
MainPage.xaml is unchanged from Part 3.
MainPage.xaml.cs/vb
MainPage.xaml.cs/vb is unchanged from Part 3.
PhotoPage.xaml
<Page
x:Name="pageRoot"
x:Class="HelloWorld.PhotoPage"
DataContext="{Binding DefaultViewModel, RelativeSource={RelativeSource Self}}"
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:HelloWorld"
xmlns:common="using:HelloWorld.Common"
xmlns:d="https://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="https://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" NavigationCacheMode="Enabled"
SizeChanged="PhotoPage_SizeChanged">
<Page.Resources>
<common:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
<!-- TODO: Delete this line if the key AppName is declared in App.xaml -->
<x:String x:Key="AppName">Hello, photo!</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 Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
<Grid.ChildrenTransitions>
<TransitionCollection>
<EntranceThemeTransition/>
</TransitionCollection>
</Grid.ChildrenTransitions>
<Grid.RowDefinitions>
<RowDefinition Height="140"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<!-- Back button and page title -->
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="120"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<AppBarButton x:Name="backButton" Icon="Back" Height="95" Margin="10,46,10,0"
Command="{Binding NavigationHelper.GoBackCommand, ElementName=pageRoot}"
Visibility="{Binding IsEnabled, Converter={StaticResource BooleanToVisibilityConverter}, RelativeSource={RelativeSource Mode=Self}}"
AutomationProperties.Name="Back"
AutomationProperties.AutomationId="BackButton"
AutomationProperties.ItemType="Navigation Button"/>
<TextBlock x:Name="pageTitle" Text="{StaticResource AppName}" Style="{StaticResource HeaderTextBlockStyle}" Grid.Column="1"
IsHitTestVisible="false" TextWrapping="NoWrap" VerticalAlignment="Bottom" Margin="0,0,30,40"/>
</Grid>
<Grid x:Name="contentGrid" Grid.Row="1" Margin="120,0,0,120">
<Grid.RowDefinitions>
<RowDefinition Height="50"/>
<RowDefinition Height="70"/>
<RowDefinition/>
</Grid.RowDefinitions>
<Button Content="Get photo" Click="GetPhotoButton_Click"/>
<TextBlock Grid.Row="1" TextWrapping="Wrap" Text="{Binding DisplayName}" Style="{ThemeResource SubheaderTextBlockStyle}"/>
<StackPanel x:Name="imagePanel" Grid.Row="2" Orientation="Horizontal">
<Border BorderBrush="Gray" BorderThickness="1" Background="Gray">
<Image x:Name="displayImage" Source="Assets/Logo.png"/>
</Border>
<StackPanel Margin="20,0,0,0">
<TextBlock TextWrapping="Wrap" Text="File name:"
Style="{ThemeResource CaptionTextBlockStyle}"/>
<TextBlock TextWrapping="Wrap" Text="{Binding Name}"
Style="{ThemeResource BodyTextBlockStyle}" Margin="10,0,0,30"/>
<TextBlock TextWrapping="Wrap" Text="Path:"
Style="{ThemeResource CaptionTextBlockStyle}"/>
<TextBlock TextWrapping="Wrap" Text="{Binding Path}"
Style="{ThemeResource BodyTextBlockStyle}" Margin="10,0,0,30"/>
<TextBlock TextWrapping="Wrap" Text="Date created:"
Style="{ThemeResource CaptionTextBlockStyle}"/>
<TextBlock TextWrapping="Wrap" Text="{Binding DateCreated.Date}"
Style="{ThemeResource BodyTextBlockStyle}" Margin="10,0,0,30" />
</StackPanel>
</StackPanel>
</Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup>
<VisualState x:Name="DefaultLayout">
<Storyboard>
</Storyboard>
</VisualState>
<VisualState x:Name="PortraitLayout">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(StackPanel.Orientation)"
Storyboard.TargetName="imagePanel">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Orientation>Vertical</Orientation>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.Margin)"
Storyboard.TargetName="imagePanel">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Thickness>0,0,20,0</Thickness>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
</Grid>
</Page>
PhotoPage.xaml.cs/vb
using HelloWorld.Common;
using System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
// The Basic Page item template is documented at https://go.microsoft.com/fwlink/p/?LinkID=234237
namespace HelloWorld
{
/// <summary>
/// A basic page that provides characteristics common to most applications.
/// </summary>
public sealed partial class PhotoPage : Page
{
private string mruToken = null;
private NavigationHelper navigationHelper;
private ObservableDictionary defaultViewModel = new ObservableDictionary();
/// <summary>
/// This can be changed to a strongly typed view model.
/// </summary>
public ObservableDictionary DefaultViewModel
{
get { return this.defaultViewModel; }
}
/// <summary>
/// NavigationHelper is used on each page to aid in navigation and
/// process lifetime management
/// </summary>
public NavigationHelper NavigationHelper
{
get { return this.navigationHelper; }
}
public PhotoPage()
{
this.InitializeComponent();
this.navigationHelper = new NavigationHelper(this);
this.navigationHelper.LoadState += navigationHelper_LoadState;
this.navigationHelper.SaveState += navigationHelper_SaveState;
}
/// <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>
private async void navigationHelper_LoadState(object sender, LoadStateEventArgs e)
{
if (e.PageState != null && e.PageState.ContainsKey("mruToken"))
{
object value = null;
if (e.PageState.TryGetValue("mruToken", out value))
{
if (value != null)
{
mruToken = value.ToString();
// Open the file via the token that you stored when adding this file into the MRU list.
Windows.Storage.StorageFile file =
await Windows.Storage.AccessCache.StorageApplicationPermissions.MostRecentlyUsedList.GetFileAsync(mruToken);
if (file != null)
{
// Open a stream for the selected file.
Windows.Storage.Streams.IRandomAccessStream fileStream =
await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
// Set the image source to a bitmap.
Windows.UI.Xaml.Media.Imaging.BitmapImage bitmapImage =
new Windows.UI.Xaml.Media.Imaging.BitmapImage();
bitmapImage.SetSource(fileStream);
displayImage.Source = bitmapImage;
// Set the data context for the page.
this.DataContext = file;
}
}
}
}
}
/// <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>
private void navigationHelper_SaveState(object sender, SaveStateEventArgs e)
{
if (!string.IsNullOrEmpty(mruToken))
{
e.PageState["mruToken"] = mruToken;
}
}
#region NavigationHelper registration
/// The methods provided in this section are simply used to allow
/// NavigationHelper to respond to the page's navigation methods.
///
/// Page specific logic should be placed in event handlers for the
/// <see cref="GridCS.Common.NavigationHelper.LoadState"/>
/// and <see cref="GridCS.Common.NavigationHelper.SaveState"/>.
/// The navigation parameter is available in the LoadState method
/// in addition to page state preserved during an earlier session.
protected override void OnNavigatedTo(NavigationEventArgs e)
{
navigationHelper.OnNavigatedTo(e);
}
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
navigationHelper.OnNavigatedFrom(e);
}
#endregion
private async void GetPhotoButton_Click(object sender, RoutedEventArgs e)
{
Windows.Storage.Pickers.FileOpenPicker openPicker = new Windows.Storage.Pickers.FileOpenPicker();
openPicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.PicturesLibrary;
openPicker.ViewMode = Windows.Storage.Pickers.PickerViewMode.Thumbnail;
// Filter to include a sample subset of file types.
openPicker.FileTypeFilter.Clear();
openPicker.FileTypeFilter.Add(".bmp");
openPicker.FileTypeFilter.Add(".png");
openPicker.FileTypeFilter.Add(".jpeg");
openPicker.FileTypeFilter.Add(".jpg");
// Open the file picker.
Windows.Storage.StorageFile file = await openPicker.PickSingleFileAsync();
// file is null if user cancels the file picker.
if (file != null)
{
// Open a stream for the selected file.
Windows.Storage.Streams.IRandomAccessStream fileStream =
await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
// Set the image source to the selected bitmap.
Windows.UI.Xaml.Media.Imaging.BitmapImage bitmapImage =
new Windows.UI.Xaml.Media.Imaging.BitmapImage();
bitmapImage.SetSource(fileStream);
displayImage.Source = bitmapImage;
this.DataContext = file;
// Add picked file to MostRecentlyUsedList.
mruToken = Windows.Storage.AccessCache.StorageApplicationPermissions.MostRecentlyUsedList.Add(file);
}
}
private void PhotoPage_SizeChanged(object sender, SizeChangedEventArgs e)
{
if (e.NewSize.Height / e.NewSize.Width >= 1)
{
VisualStateManager.GoToState(this, "PortraitLayout", true);
}
else
{
VisualStateManager.GoToState(this, "DefaultLayout", true);
}
}
}
}
' The Basic Page item template is documented at https://go.microsoft.com/fwlink/p/?LinkID=234237
''' <summary>
''' A basic page that provides characteristics common to most applications.
''' </summary>
Public NotInheritable Class PhotoPage
Inherits Page
Private mruToken As String = Nothing
''' <summary>
''' NavigationHelper is used on each page to aid in navigation and
''' process lifetime management
''' </summary>
Public ReadOnly Property NavigationHelper As Common.NavigationHelper
Get
Return Me._navigationHelper
End Get
End Property
Private _navigationHelper As Common.NavigationHelper
''' <summary>
''' This can be changed to a strongly typed view model.
''' </summary>
Public ReadOnly Property DefaultViewModel As Common.ObservableDictionary
Get
Return Me._defaultViewModel
End Get
End Property
Private _defaultViewModel As New Common.ObservableDictionary()
Public Sub New()
InitializeComponent()
Me._navigationHelper = New Common.NavigationHelper(Me)
AddHandler Me._navigationHelper.LoadState, AddressOf NavigationHelper_LoadState
AddHandler Me._navigationHelper.SaveState, AddressOf NavigationHelper_SaveState
End Sub
''' <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="sender">
''' The source of the event; typically <see cref="NavigationHelper"/>
''' </param>
''' <param name="e">Event data that provides both the navigation parameter passed to
''' <see cref="Frame.Navigate"/> when this page was initially requested and
''' a dictionary of state preserved by this page during an earlier
''' session. The state will be null the first time a page is visited.</param>
Private Async Sub NavigationHelper_LoadState(sender As Object, e As Common.LoadStateEventArgs)
If e.PageState IsNot Nothing AndAlso e.PageState.ContainsKey("mruToken") Then
Dim value As Object = Nothing
If e.PageState.TryGetValue("mruToken", value) Then
If (value IsNot Nothing) Then
mruToken = value.ToString()
' Open the file via the token that you stored when adding this file into the MRU list.
Dim file =
Await Windows.Storage.AccessCache.StorageApplicationPermissions.MostRecentlyUsedList.GetFileAsync(mruToken)
If (file IsNot Nothing) Then
' Open a stream for the selected file.
Dim fileStream = Await file.OpenAsync(Windows.Storage.FileAccessMode.Read)
' Set the image source to a bitmap.
Dim BitmapImage = New Windows.UI.Xaml.Media.Imaging.BitmapImage()
BitmapImage.SetSource(fileStream)
displayImage.Source = BitmapImage
' Set the data context for the page.
Me.DataContext = file
End If
End If
End If
End If
End Sub
''' <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="Common.SuspensionManager.SessionState"/>.
''' </summary>
''' <param name="sender">
''' The source of the event; typically <see cref="NavigationHelper"/>
''' </param>
''' <param name="e">Event data that provides a dictionary of state preserved by this page
''' during an earlier session. The state will be null the first time a page is visited.</param>
Private Sub NavigationHelper_SaveState(sender As Object, e As Common.SaveStateEventArgs)
If Not String.IsNullOrEmpty(mruToken) Then
e.PageState("mruToken") = mruToken
End If
End Sub
#Region "NavigationHelper registration"
''' The methods provided in this section are simply used to allow
''' NavigationHelper to respond to the page's navigation methods.
'''
''' Page specific logic should be placed in event handlers for the
''' <see cref="Common.NavigationHelper.LoadState"/>
''' and <see cref="Common.NavigationHelper.SaveState"/>.
''' The navigation parameter is available in the LoadState method
''' in addition to page state preserved during an earlier session.
Protected Overrides Sub OnNavigatedTo(e As NavigationEventArgs)
_navigationHelper.OnNavigatedTo(e)
End Sub
Protected Overrides Sub OnNavigatedFrom(e As NavigationEventArgs)
_navigationHelper.OnNavigatedFrom(e)
End Sub
#End Region
Private Sub PhotoPage_SizeChanged(sender As Object, e As SizeChangedEventArgs) Handles pageRoot.SizeChanged
If e.NewSize.Height / e.NewSize.Width >= 1 Then
VisualStateManager.GoToState(Me, "PortraitLayout", True)
Else
VisualStateManager.GoToState(Me, "DefaultLayout", True)
End If
End Sub
Private Async Sub GetPhotoButton_Click(sender As Object, e As RoutedEventArgs)
Dim openPicker = New Windows.Storage.Pickers.FileOpenPicker()
openPicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.PicturesLibrary
openPicker.ViewMode = Windows.Storage.Pickers.PickerViewMode.Thumbnail
' Filter to include a sample subset of file types.
openPicker.FileTypeFilter.Clear()
openPicker.FileTypeFilter.Add(".bmp")
openPicker.FileTypeFilter.Add(".png")
openPicker.FileTypeFilter.Add(".jpeg")
openPicker.FileTypeFilter.Add(".jpg")
' Open the file picker.
Dim file = Await openPicker.PickSingleFileAsync()
' file is null if user cancels the file picker.
If file IsNot Nothing Then
' Open a stream for the selected file.
Dim fileStream = Await file.OpenAsync(Windows.Storage.FileAccessMode.Read)
' Set the image source to the selected bitmap.
Dim BitmapImage = New Windows.UI.Xaml.Media.Imaging.BitmapImage()
BitmapImage.SetSource(fileStream)
displayImage.Source = BitmapImage
Me.DataContext = file
' Add picked file to MostRecentlyUsedList.
mruToken = Windows.Storage.AccessCache.StorageApplicationPermissions.MostRecentlyUsedList.Add(file)
End If
End Sub
End Class