将来自 Firebase 的坐标表示为 Annotations Swift

Question

我无法在地图上添加上传到 Firebase 的纵向和纬度注释。我想为我的所有用户添加一个注释，但无法让 xcode 识别我的 userLatitude 和 userLongitude 变量在另一个函数中。

任何事情都会有所帮助！

    func retrieveUsers(){
        let ref = Database.database().reference()
        ref.child("users").queryOrderedByKey().observeSingleEvent(of: .value, with: { snapshot in
            let users = snapshot.value as! [String: AnyObject]
            self.user.removeAll()
            for (_,value) in users {
                if let uid = value["uid"] as? String {
                    if uid != Auth.auth().currentUser!.uid {
                        let userToShow = User()
                        if let fullName = value["full name"] as? String,
                        let imagePath = value["urlToImage"] as? String,
                        //String(format: "%f", self.currentUserLocation?.longitude ?? 0),
                        let userLongitude = value["long"] as? CLLocationDegrees,
                        let userLatitude = value["lat"] as? CLLocationDegrees
                        //why isnt it recognizing the users degrees
                        {
                            userToShow.fullName = value["full name"] as? String
                            userToShow.imagePath = value["urlToImage"] as? String
                            userToShow.userID = value["uid"] as? String
                            userToShow.userLongitude = value["long"] as? CLLocationDegrees
                            userToShow.userLatitude = value["lat"] as? CLLocationDegrees
                            self.user.append(userToShow)
                        }

                    }
                }
            }
            DispatchQueue.main.async {
                self.map.reloadInputViews()
                //not sure if this is right
            }
        })
    }


    func mapView(_ mapView: MKMapView, didAdd views: [MKAnnotationView]) {
        let otherUserLocation: CLLocationCoordinate2D = CLLocationCoordinate2DMake(userLatitude, userLongitude)
        let userAnnotation = MKPointAnnotation()
        userAnnotation.coordinate = otherUserLocation
        userAnnotation.title = "fullName"


    }

Answer 1

如果你通过as? String更改as? CLLocationDegrees并在之后管理CLLocationDegrees中的演员表？

因为我认为，在Firebase中，数据存储为字符串而不是双精度（这是CLLocationDegrees类型所指的数据类型）。