Question

我的GeoFire查询带回了用户ID或keys。我按顺序取回keys，但我得到了几个序列。我怎样才能得到最后更新的序列？

@IBAction func friendsNearMeACTN(sender: AnyObject)
    {
        let geofireRef = self.ref.child("UserLocations")
        let geoFire = GeoFire(firebaseRef: geofireRef)
        let circleQuery = geoFire.queryAtLocation(self.location, withRadius: 20.6)
        circleQuery.observeEventType(.KeyEntered, withBlock: { (key: String!, location: CLLocation!) in
            self.localUsers.append(key)
            self.getLocalUsers()
        })
    }

func getLocalUsers()
{
    print(self.localUsers)

}

这是我从func getLocalUsers() ....

回来的

["WGueYzDjH4NW2vneHOyGmjf6PYB3"]
["WGueYzDjH4NW2vneHOyGmjf6PYB3", "Cg4pQj36ttNUuWNqtc16tIFmI0A2"]
["WGueYzDjH4NW2vneHOyGmjf6PYB3", "Cg4pQj36ttNUuWNqtc16tIFmI0A2", "N5pgqGEhW2f7PGGVmB3AQ8v1uPk2"]

我怎样才能简单地获取最后一个数组？

Answer 1

答案是GeoFire查询是一个连续的异步调用，需要最终代码observeReadyWithBlock才能仅为self.localUsers()提供所收集的信息。这是一个例子......

let regionQuery = geoFire.queryWithRegion(self.region)
        regionQuery.observeEventType(.KeyEntered,  withBlock: { (key: String!, location: CLLocation!) in
            var users = [String]()
            users.append(key)
            for keys in users
            {
                let user = keys
                allKeys.append(user)
            }
            self.localUsers = allKeys
            self.getLocalUsers()
        })

        regionQuery.observeReadyWithBlock({ () -> Void in
            self.getLocalUsers()
        })

Answer 2

这里的问题是每次触发观察者块时都要调用getLocalUsers函数。你是为每一个结果调用它。每次执行观察器块时，都需要计算结果并将计数加1。当计数达到结果计数时，请调用getLocalUsers函数一次而不是3次。请尝试下面的代码。我没有测试过。

@IBAction func friendsNearMeACTN(sender: AnyObject){
    var i = 0//The counter
    let geofireRef = self.ref.child("UserLocations")
    let geoFire = GeoFire(firebaseRef: geofireRef)
    let circleQuery = geoFire.queryAtLocation(self.location, withRadius: 20.6)
    circleQuery.observeEventType(.KeyEntered, withBlock: { (key: String!, location: CLLocation!) in
        self.localUsers.append(key)
        i += 1//Add one to i every time observer fires
        if i == self.key.count {//if counter (i) is equal to the keys returned call getLocalUsers func once
            self.getLocalUsers()
        }
    })
}

func getLocalUsers(){
    print(self.localUsers)
}

如何使用Swift使用Firebase GeoFire查询多个密钥？

2 个答案: