• • 背景**

我正在尝试构建一个类，它可以轻松地将字符串（如地址）转换为CLLocationCoordinate2D，以备将来使用，并将其保存到数据库中。
我有一个类似下面的类：

final class PublishMapData: ObservableObject {
    
    @Published var userAddressLat: Double = 0.0
    @Published var userAddressLong: Double = 0.0
    
    func saveMapData(address: String){
        let address = "One Apple Park Way, Cupertino, CA 95014" //simulating the call from a save button for instance
        convertAddress(address: address)
        print(String(userAddressLat)) //this prints 0.0
        print(String(userAddressLong)) //this print 0.0
        //{...extra code here...}
        //this is where I would be storing the coordinates into something like Firestore for later use
    }
    
    
    func convertAddress(address: String) {
        getCoordinate(addressString: address) { (location, error) in
            if error != nil {
                
                return
            }
            DispatchQueue.main.async {
                self.userAddressLat = location.latitude
                print(self.userAddressLat) //this prints the correct value
                self.userAddressLong = location.longitude
                print(self.userAddressLong) //this prints the correct value
            }
        }
    }

    private func getCoordinate(addressString : String, completionHandler: @escaping(CLLocationCoordinate2D, NSError?) -> Void ) {
        let geocoder = CLGeocoder()
        geocoder.geocodeAddressString(addressString) { (placemarks, error) in
            if error == nil {
                if let placemark = placemarks?[0] {
                    let location = placemark.location!
                        
                    completionHandler(location.coordinate, nil)
                    
                    return
                }
            }
                
            completionHandler(kCLLocationCoordinate2DInvalid, error as NSError?)
        }
    }

}

由于某种原因，我无法从convertAddress函数中获取lat、long值，从而无法正确存储在@Published变量中。我做错了什么？我仍在学习Swift。提前感谢您的帮助。