swift - 解析查询：按另一个数组中的元素排序

Question

好的，我很接近弄清楚这一点。我在用户名数组中有用户名。我正在尝试进行查询，根据用户名数组中的序列对结果进行排序。我尝试使用 NSSortDescriptor，但我不认为它可以做到这一点。谢谢

func photoQuery () {
    let descriptor: NSSortDescriptor = NSSortDescriptor(key: "usernameArray", ascending: false)
    let photoQuery = PFQuery(className: "UserPhoto")
    photoQuery.whereKey("username", containedIn: usernameArray)
    photoQuery.order(by: descriptor)
    photoQuery.findObjectsInBackground(block: { (objects: [PFObject]?, error: Error?) in
        if let objects = objects {
            for object in objects {
                if error == nil {
                    let userImageFile = object["photo"] as? PFFileObject
                    let urlString = userImageFile?.url as! String
                    if let url = URL(string: urlString) {
                        let data = try? Data(contentsOf: url)
                        if let imageData = data {
                            self.urlArray.append(urlString as NSString)
                            self.cache.setObject(UIImage(data:imageData)!, forKey: urlString as NSString)

                        }
                    }
                }
            }
        }
    })
}

标签： swiftuitableviewcachingparse-platform