Ios FBRequestConnection没有获取用户名？

你好，我被困在一个位置，我无法在Facebook上获得用户的用户名

    - (void)makeRequestForUserData
{
    [FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
     {
         if (!error)
         {

             // Success! Include your code to handle the results here
          NSLog("%@",result);
           NSString*  strUserName = [result objectForKey:@"username"];
             [[NSUserDefaults standardUserDefaults] setValue:strUserName forKey:FBUSER_NAME];
             [[NSUserDefaults standardUserDefaults] synchronize];

         }
         else
         {
             // An error occurred, we need to handle the error
             // Check out our error handling guide: https://developers.facebook.com/docs/ios/errors/
             NSLog(@"Error : %@", error.description);
         }
     }];
}

控制台o/p

    {
    "first_name" = XXX;
    gender = male;
    id = 4454545454;
    "last_name" = System;
    link = "https://www.facebook.com/app_scoped_user_id/4454545454
486934488/";
    locale = "en_US";
    name = “XXX”;
    timezone = "5.5";
    "updated_time" = "2014-02-28T09:20:26+0000";
    verified = 1;
}

这里我缺少用户名？原因是什么。我查过许可证了

NSLog(@"permissions::%@",FBSession.activeSession.permissions);

其输出类似于：权限：： 公众档案

---

如果您在其他设置中做得很好，这将起作用

[[FBRequest requestForMe] startWithCompletionHandler: ^(FBRequestConnection *connection,
                                                                 NSDictionary<FBGraphUser> *user,
                                                                 NSError *error) {
             if (!error) {
                       NSDictionary *userData = user; 
             }