Question

我正在使用subprocess.check_call(command.split(" "),shell=True)并尝试实施Firebase，例如Facebook或Instagram。

我已经编写了一些代码，但是我注意到，当用户多次点击类似按钮时，喜欢的次数有时会增加不止一次，非常快。

...代码

Like Button

如何实现LIKE / UNLIKE功能等同步功能？我认为我可以使用func handleLike(likeButton: UIButton, numberLabel: UILabel) { guard let uid = FIRAuth.auth()?.currentUser?.uid else { return } if let photoId = photo?.id { let ref = FIRDatabase.database().reference() let photoRef = ref.child("users").child(uid).child("likes").child(photoId) photoRef.observeSingleEventOfType(.Value, withBlock: { (snapshot) in if snapshot.value is NSNull { likeButton.setImage(UIImage(named: "LikeFilled"), forState: .Normal) likeButton.setTitleColor(UIColor.redColor(), forState: .Normal) ref.child("users").child(uid).child("likes").child(photoId).setValue(true) ref.child("photos").child(photoId).child("likes").child(uid).setValue(true) self.photo?.adjustLikes(true) if let numberofLikes = self.photo?.numberofLikes { ref.child("photos").child(photoId).child("numberofLikes").setValue(numberofLikes) numberLabel.text = String(numberofLikes) + "Likes" } } else { likeButton.setImage(UIImage(named: "UNLike"), forState: .Normal) likeButton.setTitleColor(UIColor(r:143, g: 150, b: 163), forState: .Normal) ref.child("users").child(uid).child("likes").child(photoId).removeValue() ref.child("photos").child(photoId).child("likes").child(uid).removeValue() self.photo?.adjustLikes(false) ref.child("photos").child(photoId).child("numberofLikes").setValue(self.photo?.numberofLikes) if let numberofLikes = self.photo?.numberofLikes { ref.child("photos").child(photoId).child("numberofLikes").setValue(numberofLikes) numberLabel.text = String(numberofLikes) + "Likes" } } }, withCancelBlock: nil) } } class Photo: NSObject { func adjustLikes(addLike: Bool) { if addLike { numberofLikes = numberofLikes! + 1 } else { numberofLikes = numberofLikes! - 1 } } }，但我无法用with CompletionBlock实现它...

我感谢任何帮助...

Answer 1

我一直在努力实现像计数器一样但是使用解析作为baas。我采用的最佳解决方案是不直接更新服务器上的计数器值，但是在具有上一个状态（喜欢与否）的服务器上超时完成更新时设置超时：

检查是否喜欢并反转类似状态：liked = !liked
相应地更新本地计数器：liked ? likeCounter++ : likeCounter--
更新用户界面：likeLabel.text = "\(likeCounter)"

最后检查是否有一个定时器设置为更新服务器状态：

if(likeTimer != nil) {
        // Stop current operation
        likeTimer.invalidate()
}
//Setup a set time out 1s func
likeTimer =  NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(updateLikeCounter), userInfo: nil, repeats: false)

func updateLikeCounter(){
   //if liked == true and the like operation is not submitted to server ==> increment like counter on server . else do nothing
   //if like == false and a like operation have been submitted to server (user is in the list of users who like the image) ==> decrement like counter on server . else do nothing 
}

我希望这可以帮到你

与Firebase / Swift的功能一样

1 个答案: