public void OnSessionStateChanged(FBSession session, FBSessionState state, NSError error)
{
// FBSample logic
// Any time the session is closed, we want to display the login controller (the user
// cannot use the application unless they are logged in to Facebook). When the session
// is opened successfully, hide the login controller and show the main UI.
switch (state)
{
case FBSessionState.Open:
this.mainViewController.StartLocationManager();
if (loginViewController != null)
{
navController.TopViewController.DismissViewController(true, null);
loginViewController = null;
}
// FBSample logic
// Pre-fetch and cache the friends for the friend picker as soon as possible to improve
// responsiveness when the user tags their friends.
FBCacheDescriptor cacheDescriptor = FBFriendPickerViewController.CacheDescriptor();
cacheDescriptor.PrefetchAndCacheForSession(session);
break;
case FBSessionState.Closed:
// FBSample logic
// Once the user has logged out, we want them to be looking at the root view.
// and to clear the user Token
if (navController.TopViewController.ModalViewController != null)
navController.TopViewController.DismissViewController(false, null);
navController.PopToRootViewController(false);
FBSession.ActiveSession.CloseAndClearTokenInformation();
ShowLoginView();
break;
case FBSessionState.ClosedLoginFailed:
// if the token goes invalid we want to switch right back to
// the login view, however we do it with a slight delay in order to
// account for a race between this and the login view dissappearing
// a moment before
this.ShowLoginView();
break;
default:
break;
}
NSNotificationCenter.DefaultCenter.PostNotificationName(SCSessionStateChangedNotification, session);
if (error != null)
{
UIAlertView alertView = new UIAlertView("Error: " + ((FBErrorCode)error.Code).ToString(), error.LocalizedDescription, null, "Ok", null);
alertView.Show();
}
}
private void FacebookOpenActiveSessionCompleted(FBSession session, FBSessionState status, NSError error)
{
bool openOk = (error == null && (status == FBSessionState.Open || status == FBSessionState.OpenTokenExtended));
if (openOk)
{
FBRequestConnection.GetMe(FacebookRequestForMeCompleted);
}
else if (error != null)
{
HandleFacebookError(error);
}
}