如何观察Swift中多个节点中Firebase子值的变化?

您可以只观察整个用户结构,然后使用快照确定坐标是否是已更改的元素

usersDatabaseReference.child("users").observe(.childChanged, with: { (snapshot) in
        //Determine if coordinate has changed
 })

你还可以做的是:

func observeChildAdded(){
    usersDatabaseReference.child("users").observe(.childAdded, with: { (snapshot) in
        //Get the id of the new user added
        let id = "123"
        self.usersDatabaseReference.child("users").child(id).observe(.childChanged, with: { (snapshot) in
            self.foundSnapshot(snapshot)
        })
    })
}

func foundSnapshot(_ snapshot: DataSnapshot){
    let idChanged = snapshot.key
    //Process new coordinates
}

因此,每当你添加一个新的子对象时,它都会自动为它设置一个观察者,但它们都会被推到同一个函数