Windows Phone のネットワーク変更を検出する方法

<Grid x:Name="LayoutRoot" Background="Transparent">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <!--TitlePanel contains the name of the application and page title-->
    <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
        <TextBlock x:Name="ApplicationTitle" Text="Network Change Detector" Style="{StaticResource PhoneTextNormalStyle}"/>
    </StackPanel>

    <!--ContentPanel - place additional content here-->
    <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <TextBlock Grid.Row="0" Text="Available Network Interfaces" FontSize="{StaticResource PhoneFontSizeLarge}"/>
        <ListBox Grid.Row="1" x:Name="lbNetworkInterfaces" ItemsSource="{Binding}" Background="LightGray" >
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding}" Margin="5,5,0,5" Foreground="Black"/>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <TextBlock Grid.Row="2" Text="Events" FontSize="{StaticResource PhoneFontSizeLarge}"/>
        <ScrollViewer Grid.Row="3" Background="LightGray" BorderThickness="1">
            <ListBox x:Name="lbNetworkChanges" ItemsSource="{Binding}">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding}" Foreground="Black" 
                                    FontSize="{StaticResource PhoneFontSizeNormal}" TextWrapping="Wrap" Margin="5,10,0,10"  />
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>
        </ScrollViewer>
        <TextBlock Grid.Row="4" Text="Networking Status" FontSize="{StaticResource PhoneFontSizeLarge}"/>
        <Grid Grid.Row="5" Background="LightGray" >
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>
            <TextBlock Grid.Row="0" Grid.Column="0" Text="IsNetworkAvailable" Foreground="Black" Margin="5,5,0,5" />
            <TextBlock Grid.Row="0" Grid.Column="1" x:Name="tbIsNetworkAvailable" HorizontalAlignment="Center" Foreground="Black" />
                
            <TextBlock Grid.Row="1" Grid.Column="0" Text="IsWiFiEnabled" Foreground="Black" Margin="5,5,0,5" />
            <TextBlock Grid.Row="1" Grid.Column="1" x:Name="tbIsWiFiEnabled" HorizontalAlignment="Center" Foreground="Black"/>
                
            <TextBlock Grid.Row="2" Grid.Column="0" Text="IsCellularDataEnabled" Foreground="Black" Margin="5,5,0,5" />
            <TextBlock Grid.Row="2" Grid.Column="1" x:Name="tbIsCellularDataEnabled" HorizontalAlignment="Center" Foreground="Black"/>
        </Grid>
        <Button Grid.Row="6" x:Name="btnChangeNetworkSettings" Content="Change Network Settings" Click="btnChangeNetworkSettings_Click"/>
    </Grid>
</Grid>

using System.Collections.ObjectModel;
using Microsoft.Phone.Net.NetworkInformation;
using Microsoft.Phone.Tasks;

// List of all changes detected while the app is running.
public ObservableCollection<string> Changes { get; set; }

// List of all currently available network interfaces
public ObservableCollection<string> NetworkInterfaces { get; set; }

// Constructor
public MainPage()
{
    InitializeComponent();

    // Initialise the Changes list.
    Changes = new ObservableCollection<string>();

    // Bind the ListBox to the Changes list
    lbNetworkChanges.DataContext = Changes;

    NetworkInterfaces = new ObservableCollection<string>();
    lbNetworkInterfaces.DataContext = NetworkInterfaces;

    // Subscribe to the NetworkAvailabilityChanged event
    DeviceNetworkInformation.NetworkAvailabilityChanged += new EventHandler<NetworkNotificationEventArgs>(ChangeDetected);

    UpdateNetworkInterfaces();
    UpdateNetworkStatus();
}

// In this callback, we examine the change that was detected. In this example, we are 
// creating a simple information string and adding that to the event list on the UI. 
// In a real application, this is where you might adjust your communication connection 
// in order to take advantage of a network availability change. 
void ChangeDetected(object sender, NetworkNotificationEventArgs e)
{
    string change = string.Empty;
    switch (e.NotificationType)
    {
        case NetworkNotificationType.InterfaceConnected:
            change = "Connected to ";
            break;
        case NetworkNotificationType.InterfaceDisconnected:
            change = "Disconnected from ";
            break;
        case NetworkNotificationType.CharacteristicUpdate:
            change = "Characteristics changed for ";
            break;
        default:
            change = "Unknown change with ";
            break;
    }

    string changeInformation = String.Format(" {0} {1} {2} ({3})",
                DateTime.Now.ToString(), change, e.NetworkInterface.InterfaceName,
                e.NetworkInterface.InterfaceType.ToString());

    // We are making UI updates, so make sure these happen on the UI thread.
    Dispatcher.BeginInvoke(() =>
    {
        Changes.Add(changeInformation);
        UpdateNetworkStatus();
        UpdateNetworkInterfaces();
                
    });
           
}

private void UpdateNetworkInterfaces()
{

    NetworkInterfaces.Clear();
    NetworkInterfaceList networkInterfaceList = new NetworkInterfaceList();
    foreach (NetworkInterfaceInfo networkInterfaceInfo in networkInterfaceList)
    {
        NetworkInterfaces.Add(networkInterfaceInfo.InterfaceName);
    }
}

private void UpdateNetworkStatus()
{
    tbIsCellularDataEnabled.Text = (DeviceNetworkInformation.IsCellularDataEnabled) ? "Yes" : "No";
    tbIsNetworkAvailable.Text = (DeviceNetworkInformation.IsNetworkAvailable) ? "Yes" : "No";
    tbIsWiFiEnabled.Text = (DeviceNetworkInformation.IsWiFiEnabled) ? "Yes" : "No";
}

// For testing purposes, we provide a way to change the network connection
// settings by launching the ConnectionSettingsTask. However, because we are moving 
// our application to the background and then to the foreground when we navigate back from
// the ConnectionSettingTask, there is a chance we may not receive all NetworkAvailabilityChanged events.
// Alternatively, you can test by physically disconnecting a Wi-Fi connection, by connecting and disconnecting
// your device to your desktop, or by moving out of range of your Wi-Fi network.
private void btnChangeNetworkSettings_Click(object sender, RoutedEventArgs e)
{
    MessageBox.Show("This action will launch the ConnectionSettingsTask where you can change the network settings." + 
                        " As soon as you have made your changes, use the hardware Back button to get back to this page so that you can observe the NetworkAvailabilityChanged events.");

    //Use the ConnectionSettingsTask to bring up the connection settings
    ConnectionSettingsTask connectionSettings = new ConnectionSettingsTask();

    // We are using the Connection Settings page for AirplaneMode.
    connectionSettings.ConnectionSettingsType = ConnectionSettingsType.AirplaneMode;
    connectionSettings.Show();

    // Note: Once you have changed the settings (switched from On to Off for example)
    // use the hardward Back button on your device to go back to this page and catch
    // the NetworkAvailabilityChanged events.
}