在iOS 7中从Facebook获取我朋友的个人资料图片和名称

Question

我正在尝试从Facebook获取我的朋友个人资料图片和名称。我在facebook上创建了一个应用程序，并在.plist中添加了“FacebookAppID”，“FacebookDisplayName”和“URL Type”。但我无法提取信息。它是关于Facebook应用程序的权限？如果是的话，我怎样才能获得Facebook的权限。

这是我的代码部分;

- (IBAction)loginButtonTapped:(id)sender {

NSArray *permissionArray = [NSArray arrayWithObjects:@"user_about_me",nil];

[FBSession openActiveSessionWithReadPermissions:permissionArray  allowLoginUI:YES completionHandler:^(FBSession *session, FBSessionState state,NSError *error) {

    [self sessionStateChanged:session  state:state  error:error];

}];
}

- (void)sessionStateChanged:(FBSession *)session state:(FBSessionState) state error:(NSError  *)error
{

FBRequest* friendsRequest = [FBRequest requestForMyFriends];
[friendsRequest startWithCompletionHandler: ^(FBRequestConnection *connection,
                                              NSDictionary* result,
                                              NSError *error) {
    NSArray* friends = [result objectForKey:@"data"];

    NSLog(@"Found: %i friends", friends.count);
    NSLog(@"result: %@ friends", result);
    for (NSDictionary<FBGraphUser>* friend in friends) {
        NSLog(@"I have a friend named %@ with id %@", friend.name, friend.id);



    }
}];

}

感谢您的回答和兴趣。

最诚挚的问候。