public MainViewController () : base ("MainViewController", null)
		{
			authenticatedHandler = new GKNotificationHandler (delegate(NSError error) {
				if (GKLocalPlayer.LocalPlayer.Authenticated) {
					//Switching Users
					if(currentPlayerID != null || currentPlayerID != GKLocalPlayer.LocalPlayer.PlayerID)
					{
						currentPlayerID = GKLocalPlayer.LocalPlayer.PlayerID;
						player = new PlayerModel();
						player.loadStoredScores();
						player.loadSotredAchievements();
					}
				} else {
					var alert = new UIAlertView ("Game Center Account Required", "Need login the game center!", null, "Retry", null);
					alert.Clicked += delegate {
						GKLocalPlayer.LocalPlayer.Authenticate (authenticatedHandler);
					};
					alert.Show ();

				}
			});
		}
 public MainViewController() : base("MainViewController", null)
 {
     authenticatedHandler = new GKNotificationHandler(delegate(NSError error) {
         if (GKLocalPlayer.LocalPlayer.Authenticated)
         {
             //Switching Users
             if (currentPlayerID != null || currentPlayerID != GKLocalPlayer.LocalPlayer.PlayerID)
             {
                 currentPlayerID = GKLocalPlayer.LocalPlayer.PlayerID;
                 player          = new PlayerModel();
                 player.loadStoredScores();
                 player.loadSotredAchievements();
             }
         }
         else
         {
             var alert      = new UIAlertView("Game Center Account Required", "Need login the game center!", null, "Retry", null);
             alert.Clicked += delegate {
                 GKLocalPlayer.LocalPlayer.Authenticate(authenticatedHandler);
             };
             alert.Show();
         }
     });
 }