Question

我尝试设置一个函数来监听数据库某个部分内的更改：

private func observeParticipants() {

    let databaseRef = FIRDatabase.database().reference()

    let groupRef = databaseRef.child("groups").child(currentRoomID).child("participants")
    groupRef.observe(.childAdded, with: { snapshot in
        print("observe snapshot.value: \(snapshot.value)")
        if let snapDict = snapshot.value as? [String:AnyObject] {

            for each in snapDict {

                let uid  = each.key
                let avatar = each.value["profilePicture"] as! String
                let gender = each.value["gender"] as! String
                let handle = each.value["handle"] as! String
                let name = each.value["name"] as! String
                let status = each.value["status"] as! String

                // Set those to the dictionaries [UID : value]
                self.avatarDictionary.setValue(avatar, forKey: uid)
                self.nameDictionary.setValue(name, forKey: uid)
                self.genderDictionary.setValue(gender, forKey: uid)
                self.handleDictionary.setValue(handle, forKey: uid)
                self.statusDictionary.setValue(status, forKey: uid)
                print("\n\navatarDictionary:\n \(self.avatarDictionary)")
                print("\nhandleDictionary:\n \(self.handleDictionary)")
                print("\ngenderDictionary:\n \(self.genderDictionary)")
                print("\nnameDictionary:\n \(self.nameDictionary)")
                print("\nstatusDictionary:\n \(self.statusDictionary)")
                self.navBarCollectionView.reloadData()
            }
        }
    })
}

当我运行它时，它会加载正确的值，但如果我进行更改，例如向该组添加新用户，则它不会反映该更改。数据库更新正常，但观察者没有看到。有什么方法可以重新写这个来使观察得当吗？如果有帮助，我可以发布我的数据库结构。

谢谢！

编辑：数据库结构：

https://pastebin.com/SZ2mE2Vt

编辑：添加第二个用户后的snapshot.value：

Snapshot.value: Optional({
    gender = female;
    handle = sav;
    name = Savina;
    profilePicture = "https://graph.facebook.com/1929991317219760/picture?type=large&return_ssl_resources=1";
    status = F8B016;
})

编辑2：

这是最初用于获取所有用户值的代码，也是每次离开视图并返回时的代码。它只是作为一个观察者没有正常行动，即如果我添加一个参与者，它没有看到并更新必要的值，如集合视图。我必须离开视野，然后回来让它发生。

func getParticipantInfo() {

    let databaseRef = FIRDatabase.database().reference()

    let groupRef = databaseRef.child("groups").child(currentRoomIdGlobal)
    groupRef.observe(.childAdded, with: { snapshot in

        if let snapDict = snapshot.value as? [String : AnyObject] {

            for each in snapDict {

                let uid  = each.key
                let avatar = each.value["profilePicture"] as! String
                let gender = each.value["gender"] as! String
                let handle = each.value["handle"] as! String
                let name = each.value["name"] as! String
                let status = each.value["status"] as! String

                // Set those to the dictionaries [UID : value]
                self.avatarDictionary.setValue(avatar, forKey: uid)
                self.nameDictionary.setValue(name, forKey: uid)
                self.genderDictionary.setValue(gender, forKey: uid)
                self.handleDictionary.setValue(handle, forKey: uid)
                self.statusDictionary.setValue(status, forKey: uid)
                print("\n\navatarDictionary:\n \(self.avatarDictionary)")
                print("\nhandleDictionary:\n \(self.handleDictionary)")
                print("\ngenderDictionary:\n \(self.genderDictionary)")
                print("\nnameDictionary:\n \(self.nameDictionary)")
                print("\nstatusDictionary:\n \(self.statusDictionary)")
                self.navBarCollectionView.reloadData()
            }
        }
    })
}

Firebase观察者最初设置值，但在进行更改时不会更新

0 个答案: