迅速的Firebase移除观察者

Question

我注意到在打开视图控制器时，已触发多次喜欢或不喜欢的打印，因此我在viewDidDisappear中添加了一个移除观察器（我尝试了所有列出的操作），但它继续触发多次，有人可以帮我吗？

这是我的代码：

 private var databaseHandle: FIRDatabaseHandle!
 var ref = FIRDatabase.database().reference()
 var isLiked: Bool = false
  override func viewDidLoad() {
        super.viewDidLoad()

isLiked = false

databaseHandle = ref.child("favperuser").child(FIRAuth.auth()!.currentUser!.uid).observe( .value, with:{(snap) in

            if snap.hasChild(self.detailId){

                print("is liked")
                self.isLiked = true
                 self.likeButton.setTitle("Unlike", for: .normal)

                self.likeButton.setImage(UIImage(named: "star-")?.withRenderingMode(.alwaysOriginal), for: .normal)
                self.likeButton.setImage(UIImage(named: "star-")?.withRenderingMode(.alwaysOriginal), for: .highlighted)

            }else{

                print("not liked")
                self.isLiked = false
                self.likeButton.setTitle("Like!", for: .normal)

                self.likeButton.setImage(UIImage(named: "star+")?.withRenderingMode(.alwaysOriginal), for: .normal)
                self.likeButton.setImage(UIImage(named: "star+")?.withRenderingMode(.alwaysOriginal), for: .highlighted)

            }


          })
        self.isLiked = false

}


      @IBAction func likePressed(_ sender: UIButton) {


        if self.isLiked == false {

            ref.child("favperuser").child( FIRAuth.auth()!.currentUser!.uid).updateChildValues([detailId: true])


        } else {


            ref.child("favperuser").child( FIRAuth.auth()!.currentUser!.uid).child(detailShellId).removeValue { (error, ref) in
                if error != nil {
                    print("error \(error)")
                }
            }



        }

    }



    override func viewDidDisappear(_ animated: Bool) {
    super.viewDidDisappear(animated)

    ref.removeObserver(withHandle: databaseHandle)

    ref.child("favperuser").removeObserver(withHandle: databaseHandle)
    ref.child("favperuser").child(FIRAuth.auth()!.currentUser!.uid).removeObserver(withHandle: databaseHandle)
}

Answer 1

请参考此链接：

https://firebase.google.com/docs/database/ios/read-and-write#detach_listeners

同样，在通过处理程序删除所有引用之后，只需删除该引用的removeAllObservers即可，以防万一任何观察者离开了，它可能会继续同步，并且应该在从firebase收到快照后将其删除，因为我也面临着解决该问题的相同问题。