How to remove a GeoFire handle for the following observe in Swift?

问题

This is a question for Swift, Firebase and Geofire.

I would like to know how to remove a GeoFire handle for the following observer in Swift.

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

The following works fine (in viewDidDisappear):

locationsEnd?.firebaseRef.removeAllObservers()

However with handle it does not:

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
        })
}

I've tried the locationHandle as follows, without success:

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

Any suggestions would be great, as mentioned I can just remove all observers, but elsewhere I need to just remove a handle.

回答1:

locationHandle is defined as an UInt in your code and it needs to be a FIRDatabaseHandle so

Here's an example of removing a Firebase handle

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)
    }
}

For GeoFire it's more like this

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
})

then to remove, use the

circleQuery.removeObserverWithFirebaseHandle(queryHandle)

来源：https://stackoverflow.com/questions/41449938/how-to-remove-a-geofire-handle-for-the-following-observe-in-swift

标签

ios

swift

firebase

geofire