For anyone else looking to get the profile pic in iOS:
I just did this to get the user's Facebook pic:
NSString *profilePicURL = [NSString stringWithFormat:@"http://graph.facebook.com/%@/picture?type=large", fbUserID];
where 'fbUserID' is the Facebook user's profile ID.
This way I can always just call the url in profilePicURL to get the image, and I always get it, no problem. If you've already got the user ID, you don't need any API requests, just stick the ID into the url after facebook.com/.
FYI to anyone looking who needs the fbUserID in iOS:
if (FBSession.activeSession.isOpen) {
[[FBRequest requestForMe] startWithCompletionHandler:
^(FBRequestConnection *connection,
NSDictionary<FBGraphUser> *user,
NSError *error) {
if (!error) {
self.userName = user.name;
self.fbUserID = user.id;
}
}];
}
You'll need an active FBSession for that to work (see Facebook's docs, and the "Scrumptious" example).