在Windows Phone 8中使用Live Connect并保持登陆状态

private static readonly string[] _scopes =
          new[] { 
          "wl.signin", 
         "wl.basic" };
   
      private LiveConnectClient _connection;
      private LiveLoginResult _login;
   
      public LiveLogin()
      {
          this.Loaded += this.OnLoaded;
      }
   
      private async void OnLoaded(object sender, RoutedEventArgs routedEventArgs)
      {
          //----------------------------------------------------------------------
          // Login to skydrive
          //----------------------------------------------------------------------
          await SkydriveLogin();
      }
   
      private async Task SkydriveLogin()
      {
          try
          {
              //----------------------------------------------------------------------
              // Initialize our auth client with the client Id for our specific application
              //----------------------------------------------------------------------
              LiveAuthClient authClient = new LiveAuthClient("**your client id here**");
   
              //----------------------------------------------------------------------
              // Using InitializeAsync we can check to see if we already have an connected session
              //----------------------------------------------------------------------
              _login = await authClient.InitializeAsync(_scopes);
   
              //----------------------------------------------------------------------
              // If not connected, bring up the login screen on the device
              //----------------------------------------------------------------------
              if (_login.Status != LiveConnectSessionStatus.Connected)
              {
                  _login = await authClient.LoginAsync(_scopes);
              }
   
              //----------------------------------------------------------------------
              // Initialize our connection client with our login result
              //----------------------------------------------------------------------
              _connection = new LiveConnectClient(_login.Session);
          }
          catch (Exception ex)
          {
              //TODO: Add connection specific exception handling
          }
      }

/// <summary>
        /// live client
        /// </summary>
        public static LiveConnectClient CurrentLiveConnectClient { get; set; }

try
                {
                    string[] _scopes = new string[] { "wl.signin", "wl.basic", "wl.offline_access", "wl.skydrive", "wl.skydrive_update" };
                    LiveAuthClient authClient = new LiveAuthClient("your client id");
                    LiveLoginResult _login = await authClient.InitializeAsync(_scopes);
                    #region 如果要强制用户为登陆状态则使用以下代码
                    //if (_login.Status != LiveConnectSessionStatus.Connected)
                    //{
                    //    _login = await authClient.LoginAsync(_scopes);
                    //}
                    //App.CurrentLiveConnectClient = new LiveConnectClient(_login.Session);
                    #endregion
                    if(_login.Status == LiveConnectSessionStatus.Connected)
                    {
                        //如果为登陆状态 则设置LiveConnectClient供以后调用 否则就等到需要用户登录的时候再提示登陆
                        App.CurrentLiveConnectClient = new LiveConnectClient(_login.Session);
                    }
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(ex.Message);
                }

        private async void btnSignin_SessionChanged(object sender, LiveConnectSessionChangedEventArgs e)
        {
            if (e.Status == LiveConnectSessionStatus.Connected)
            {
                if (App.CurrentLiveConnectClient == null)
                {
                    App.CurrentLiveConnectClient = new LiveConnectClient(e.Session);
                }
                LiveOperationResult operationResult = await App.CurrentLiveConnectClient.GetAsync("me");
                try
                {
                    dynamic meResult = operationResult.Result;
                    if (meResult.first_name != null &&
                        meResult.last_name != null)
                    {
                        infoTextBlock.Text = "Hello " +
                            meResult.first_name + " " +
                            meResult.last_name + "!";
                    }
                    else
                    {
                        infoTextBlock.Text = "Hello, signed-in user!";
                    }
                }
                catch (LiveConnectException exception)
                {
                    this.infoTextBlock.Text = "Error calling API: " +
                        exception.Message;
                }
            }
            else
            {
                infoTextBlock.Text = "Not signed in.";
            }
        }