在我的应用中，我使用GeoFire来查询用户位置周围的用户。
它是一个类似Tinder的应用程序，带有卡片等......我使用KolodaView作为卡片。
func queryUsers(searchRadius: Int, center: CLLocation) {
print("Query started")
let geofireRef = Database.database().reference().child("usersLocations")
let geoFire = GeoFire(firebaseRef: geofireRef)
let circleQuery = geoFire?.query(at: center, withRadius: Double(searchRadius))
_ = circleQuery?.observe(.keyEntered, with: { (result, location) in
print("User \(result!) found")
print("Adding user \(result!)")
addUser(userID: result!, completionHandler: { (success) in
print("User added")
})
})
}
func addUser(userID: String, completionHandler:@escaping (Bool) -> ()) {
let foundUsers = UserDefaults.standard.array(forKey: "foundUsers")
let databaseRef = Database.database().reference()
databaseRef.observeSingleEvent(of: .value, with: { (snapshot) in
if (foundUsers?.count)! < 20 {
// USERS
let users = (snapshot.value as? NSDictionary)?["users"] as! NSDictionary
// USER
let user = users[userID] as! NSDictionary
getFirstUserPicture(userID: userID, completionHandler: { (data) in
if let data = data {
DispatchQueue.main.async {
user.setValue(data, forKey: "picture")
// APPEND FOUND USERS ARRAY
var foundUsers = UserDefaults.standard.array(forKey: "foundUsers")
foundUsers?.append(user)
// STORE FOUND USERS ARRAY
UserDefaults.standard.set(foundUsers, forKey: "foundUsers")
UserDefaults.standard.synchronize()
// UPDATE CARD VIEW
if foundUsers?.count == 1 {
NotificationCenter.default.post(name: .loadCardView, object: nil)
} else {
NotificationCenter.default.post(name: .loadCardsInArray, object: nil)
}
// COMPLETION
completionHandler(true)
}
}
})
}
}) { (error) in
print(error.localizedDescription)
}
}
当我启动应用程序时，将调用queryUsers函数，即查询
开始
User 1XXXXXXXXXXXXXXXX found
Adding user 1XXXXXXXXXXXXXXXX
User 2XXXXXXXXXXXXXXXX found
Adding user 2XXXXXXXXXXXXXXXX
User added
User added
addUser功能）问题在于它没有等待addUser完成为第二个找到的用户调用addUser。结果是在我的KolodaView中，第二个用户被发现了两次
因为我认为找到的第二个用户addUser的调用使用了第一个用户找到的参数。
是否可以等待第一次addUser完成并重新开始查询？或者只是在找到第一个用户后“暂停”查询，并在完成第一次addUser调用后再次启动它？
感谢您的帮助
我尝试了@ Rlee128解决方案，但没有任何改变，我有相同的输出:(：
// MARK: UPDATE USER LOCATION - FUNCTION
func updateUserLocation() {
let databaseRef = Database.database().reference().child("usersLocations")
let geoFire = GeoFire(firebaseRef: databaseRef)
let userID = UserDefaults.standard.string(forKey: "userID")!
let locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.startUpdatingLocation()
geoFire?.setLocation(locationManager.location, forKey: userID, withCompletionBlock: { (error) in
if error != nil {
print(error as Any)
} else {
// Location updated
}
})
}
// MARK: LOCATION MANAGER DELEGATE - FUNCTION
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
manager.stopUpdatingLocation()
manager.delegate = nil
}
答案 0 :(得分：1)
在调用manager.stopUpdatingLocation（）之后，位置管理器didUpdateLocations将manager.delegate设置为= nil。如果您希望我在我的代码中向您展示它的外观，请告诉我。
func findLocation() {
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
if CLLocationManager.locationServicesEnabled() {
locationManager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let userLocation = locations[0] as CLLocation
manager.stopUpdatingLocation()
manager.delegate = nil
let loc = CLLocation(latitude: userLocation.coordinate.latitude, longitude: userLocation.coordinate.longitude)
getLocation(location: loc)
}