Windows phone 8推送通知空通道uri

我知道这个问题已经提过很多次了，但找不到答案。

我正试图使用下面的代码在我的应用程序中设置推送通知，但我遇到了通道uri null问题。

我已经在4个不同的设备+模拟器上尝试了该应用程序，所有设备都在相同的网络条件下（工作WiFi-家庭WiFi-3G）其中2个设备是Lumia 920都无法获得信道uri，而其他2个设备HTC 8X和Lumia 820可以成功获得信道uri并注册推送。

模拟器也可以成功地获得通道uri。

在一个Lumia 920上，它设法获得了一个频道uri，但我再次卸载并安装了该应用程序，从那以后就无法获得任何频道uri。

以下是我的场景：

1-安装在3G上的Lumia 920 Black运行良好，卸载/重新安装在任何连接上都停止工作（3G-工作WiFi-家庭WiFi）2-Lumia 920黄色安装在3G上-工作WiFi-家庭WiFi从未设法获得频道uri3-HTC 8X在3G上-工作WiFi-家庭WiFi在所有3个网络上都很好4-Lumia 820与HTC 8X一样工作伟大的

请注意，其他应用程序上的推送通知在所有4台设备上都能正常工作。

我非常感谢对通道空uri 的任何反馈/建议

下面是我使用的代码，它与MSDN 提供的代码相同

  public MainPage()
    {
        /// Holds the push channel that is created or found.
        HttpNotificationChannel pushChannel;
        // The name of our push channel.
        string channelName = "ToastSampleChannel";
        InitializeComponent();
        // Try to find the push channel.
        pushChannel = HttpNotificationChannel.Find(channelName);
        // If the channel was not found, then create a new connection to the push service.
        if (pushChannel == null)
        {
            pushChannel = new HttpNotificationChannel(channelName);
            // Register for all the events before attempting to open the channel.
            pushChannel.ChannelUriUpdated += new EventHandler<NotificationChannelUriEventArgs>(PushChannel_ChannelUriUpdated);
            pushChannel.ErrorOccurred += new EventHandler<NotificationChannelErrorEventArgs>(PushChannel_ErrorOccurred);
            // Register for this notification only if you need to receive the notifications while your application is running.
            pushChannel.ShellToastNotificationReceived += new EventHandler<NotificationEventArgs>(PushChannel_ShellToastNotificationReceived);
            pushChannel.Open();
            // Bind this new channel for toast events.
            pushChannel.BindToShellToast();
        }
        else
        {
            // The channel was already open, so just register for all the events.
            pushChannel.ChannelUriUpdated += new EventHandler<NotificationChannelUriEventArgs>(PushChannel_ChannelUriUpdated);
            pushChannel.ErrorOccurred += new EventHandler<NotificationChannelErrorEventArgs>(PushChannel_ErrorOccurred);
            // Register for this notification only if you need to receive the notifications while your application is running.
            pushChannel.ShellToastNotificationReceived += new EventHandler<NotificationEventArgs>(PushChannel_ShellToastNotificationReceived);
            // Display the URI for testing purposes. Normally, the URI would be passed back to your web service at this point.
            System.Diagnostics.Debug.WriteLine(pushChannel.ChannelUri.ToString());
            MessageBox.Show(String.Format("Channel Uri is {0}",
                pushChannel.ChannelUri.ToString()));
        }
    }