如何在 Swift 中为以下观察删除 GeoFire 句柄？

Question

这是一个针对 Swift、Firebase 和 Geofire 的问题。

我想知道如何在 Swift 中为以下观察者移除 GeoFire 句柄。

locationsEnd!.query(at: location, withRadius: 16.0).observe(GFEventType.init(rawValue: 0)!, with: {(key, location) in

以下工作正常（在 viewDidDisappear 中）：

locationsEnd?.firebaseRef.removeAllObservers()

但是使用句柄却没有：

var locationHandle: UInt = 0

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

    //following does not work:
    locationsEnd?.firebaseRef.removeObserver(withHandle: locationHandle)
}

func aroundMe(_ location: CLLocation){

        locationHandle = locationsEnd!.query(at: location, withRadius: 16.0).observe(GFEventType.init(rawValue: 0)!, with: {(key, location) in

            //etc
        })
}

我已经按如下方式尝试了locationHandle，但没有成功：

var locationHandle = FirebaseHandle()
var locationHandle: FirebaseHandle = 0
var locationHandle: UInt!
var locationHandle: UInt = 0
var locationHandle = FIRDatabaseHandle()
var locationHandle: FirebaseHandle = 0

任何建议都会很棒，如前所述，我可以删除所有观察者，但在其他地方我只需要删除一个句柄。

Answer 1

locationHandle 在您的代码中被定义为一个 UInt，它需要是一个 FIRDatabaseHandle 所以

以下是删除 Firebase 句柄的示例

var myPostHandle : FIRDatabaseHandle?

func someFunc()
{
    myPostHandle = ref.child("posts").observeEventType(.childAdded,
      withBlock: { (snapshot) -> Void in

            let postBody = snapshot.value!["body"] as! String

    })
}

func stopObserving()
{
    if myPostHandle != nil {
        ref.child("posts").removeObserverWithHandle(myPostHandle)
    }
}

对于 GeoFire，它更像这样

let geofireRef = FIRDatabase.database().reference()
let geoFire = GeoFire(firebaseRef: geofireRef)
let center = CLLocation(latitude: 37.7832889, longitude: -122.4056973)
var circleQuery = geoFire.queryAtLocation(center, withRadius: 0.6)

var queryHandle = circleQuery.observeEventType(.KeyEntered,
         withBlock: { (key: String!, location: CLLocation!) in
             //do something
})

然后要删除，使用

circleQuery.removeObserverWithFirebaseHandle(queryHandle)