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如何使用Swift在FireBase数据库中发生更改时获取计数值?

timer firebase function multithreading swift

0

Eniya Sri · 技术社区 · 8 年前

我不熟悉swift编程和FireBase,我已经实现了聊天应用程序,我使用发送方和接收方ID存储消息计数,在接收方获得完美的计数,但当FireBase中添加新计数时,我希望获得新的计数,因为我使用计时器每10秒调用一个函数,我获得完美的计数,但我的问题是计时器持续运行,应用程序挂起且运行缓慢,有时我没有响应,有人能建议我如何每10秒调用一次函数或如何使用计时器吗。

在这里,我尝试了这个代码,

var timer = Timer()
 override func viewWillAppear(_ animated: Bool) {
        MessageCountingFunction()
    }
   func MessageCountingFunction(){
        //getting count details
        keyvalue.removeAllObjects()
    countarray.removeAllObjects()
        let ref = FIRDatabase.database().reference()
        ref.child("CountDetails").child(AuthManager.User.id.value).observeSingleEvent(of: FIRDataEventType.value, with: { (snapshot) in
            if let cakeSnapshot = snapshot.children.allObjects as? [FIRDataSnapshot] {
                for cakes in cakeSnapshot {
                    print(cakes)
                    if let cakeDictionary = cakes.value as? Dictionary <String, Any> {
                        print(cakeDictionary)
                        let count = cakeDictionary["Count"]
                        let key = cakes.key as String
                        //your class that takes a key as String and a Dictionary
                        print(count as Any)
                        print(key)
                        self.keyvalue.add(key)
                        self.countarray.add(count!)

                    }
                }
                DispatchQueue.global().sync {
                    print(self.keyvalue)
                    print(self.countarray)
                    self.tableView.reloadData()
                }
            }

        })
    DispatchQueue.main.async {
        self.timer = Timer.scheduledTimer(timeInterval: 10, target: self, selector: #selector(self.MessageCountingFunction), userInfo: nil, repeats: true)
    }

    }

1 回复 | 直到 8 年前

1

0

Ayush Yadav 8 年前

新消息的json数据结构为:-

{“状态”:“已发送”,“发件人”:“ayush”,“时间戳”: 1525760473513}

我们正在维护状态键以检查新邮件。读取后,我们将更新状态键的值以读取并查找新邮件的发送状态。

var channelRef: DatabaseReference =   Database.database().reference().child(FIREBASE_CONSULTATION_DBKEY)     

channelRef.child("channelKey").observe(DataEventType.value, with: { (snapshot) -> Void in // 1
        if let channelData = snapshot.value as? Dictionary<String, AnyObject>{ // 2
            let id = snapshot.key
            self.chatMessageArray.removeAll()
            for (key,obj) in channelData{
               if status == "Sent"{


                }
            }
         }
      }
    }