PFObject没有成员objectforkey

Question

这是我的代码：

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)

    state = .DefaultMode

    // fill the cache of a user's followees
    ParseHelper.getFollowingUsersForUser(PFUser.currentUser()!) { (results: [PFObject]?, error: NSError?) -> Void in
        let relations = results
        // use map to extract the User from a Follow object
        self.followingUsers = relations.map {
            $0.objectForKey(ParseHelper.ParseFollowToUser) as! PFUser
        }
    }
}

我的错误：

  

类型的价值＆＃39; [PFObject]＆＃39;没有会员＆＃39; objectForKey＆＃39;

Answer 1

我猜它是因为[PFObjects]数组是可选的，还没有解开。

if let relations = results {
    // use map to extract the User from a Follow object
    self.followingUsers = relations.map {
        $0.objectForKey(ParseHelper.ParseFollowToUser) as! PFUser
    }
}