我正在与 Firebase 共享和检索坐标,但是当我在我的控制台中打印它们时......我得到了 3-4 次相同的坐标。 这对我的自定义标记图像文件产生了奇怪的影响。 如何仅从 Firebase 获取一次坐标?
这是我的代码:
var posts=[postStruct]()
var mapView : GMSMapView? = nil
var friendLocator : [Locator] = [Locator]()
struct Locator {
let name: String
let long: CLLocationDegrees
let lat: CLLocationDegrees
}
var latPass: Double!
var longPass: Double!
var fetchLat: Double!
var fetchLong: Double!
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
{
var location=locations[0]
let span:MKCoordinateSpan=MKCoordinateSpanMake(0.01, 0.01)
var myLocation:CLLocationCoordinate2D=CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)
let region:MKCoordinateRegion=MKCoordinateRegionMake(myLocation, span)
latPass=28.3217378
longPass=75.6895935
post()
self.configureMapView()
let dataBaseRef=FIRDatabase.database().reference()
dataBaseRef.child("Raunak Trikha").queryOrderedByKey().observeSingleEvent(of: .childAdded, with: {(snapshot) in
let postDict = snapshot.value as? [String : AnyObject] ?? [:]
var fetchLat = postDict["lat"] as! Double
var fetchLong = postDict["long"] as! Double
let locator = Locator(name: "Raunak Trikha", long: fetchLong, lat: fetchLat)
self.friendLocator.append(locator)
self.locateFriend()
print(fetchLat)
print(fetchLong)
})
manager.stopUpdatingLocation()
self.view = mapView
}
func locateFriend() {
for friend in friendLocator{
let friendMarker = GMSMarker()
friendMarker.position=CLLocationCoordinate2D(latitude: friend.lat, longitude: friend.long)
friendMarker.title=friend.name
friendMarker.map=mapView
mapView?.selectedMarker=friendMarker
if friend.name=="Virat Singh"{
friendMarker.icon=UIImage(named: "ViratPin.png")
}
else if friend.name=="Raunak Trikha"{
friendMarker.icon=UIImage(named: "currentLocation.png")
}
}
do {
mapView?.mapStyle = try GMSMapStyle(jsonString: kMapStyle)
} catch {
NSLog("One or more of the map styles failed to load. \(error)")
}
}
func configureMapView(){
let camera = GMSCameraPosition.camera(withLatitude: latPass, longitude: longPass, zoom: 10)
self.mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
view = mapView
mapView?.settings.scrollGestures = true
mapView?.settings.zoomGestures = true
mapView?.settings.myLocationButton = true
//mapView?.addSubview(searchBar)
//mapView?.addSubview(searchSupporter)
//mapView?.bringSubview(toFront: searchBar)
for gesture in (mapView?.gestureRecognizers!)! {
mapView?.removeGestureRecognizer(gesture)
}
}
当我打印 fetchLat
和 fetchLong
时,我得到了 4 次相同的坐标,它与我的自定义标记图像重叠,产生了奇怪的效果。
最佳答案
由于添加特定 Locator
结构的代码被多次调用,因此在将其添加到本地数组之前检查您的数组以确保它不包含完全相同的结构。
这将评估您的结构数组并确定它是否没有值(value)。但它还假定结构的 name
属性是每个结构的唯一标识符,这可能不是您的情况。您也可以比较 filter
闭包中要确保没有重复的任何值,即。 e. lat
和 long
。
let locator = Locator(name: "Raunak Trikha", long: fetchLong, lat: fetchLat)
if self.friendLocator.filter({ $0.name == locator.name }).count == 0 {
self.friendLocator.append(locator)
}
self.locateFriend()
关于ios - 如何从 Firebase 获取单个数据库引用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/46279864/