Return CLLocationCoordinate2D 结构

Question

我是编程新手，我的问题是如何将变量类型 CLLocationCoordinate2D 的数据return 转换为坐标，即结构类型。尝试开发天气应用程序。

我有一个结构：

struct Coordinates {
    let latitude: Double
    let longitude: Double
}

我的代码如下所示：

//getting coordinates from String
func getCoordinateFrom(address: String, completion: @escaping(_ coordinate: CLLocationCoordinate2D?, _ error: Error?) -> () ) {
                CLGeocoder().geocodeAddressString(address) { placemarks, error in
                    completion(placemarks?.first?.location?.coordinate, error)
                }
            }

//When the User type his city, coordinates have type of CLLocationCoordinate2D    
@IBAction func changeCityButtonPressed(_ sender: UIButton) {
            guard let address = textField.text else { return }
            getCoordinateFrom(address: address) { coordinate, error in
                guard let coordinate = coordinate, error == nil else { return }
                DispatchQueue.main.async {
                    print(coordinate)
                }  
            }
        }

我有一个常量，我的任务是将坐标从函数转移到这个常量。

  let coordinates = Coordinates(latitude: 00.617366, longitude: 37.617366)

问题是函数中的这些坐标是闭包的。所以我不能 return 他们等等。我试图找到正确的答案但没有结果。有人有一些 advice/solution?

Answer 1

这一行：

 let coordinates = Coordinates(latitude: 00.617366, longitude: 37.617366)

将let替换为var

在此代码中：

  @IBAction func changeCityButtonPressed(_ sender: UIButton) {
        guard let address = textField.text else { return }
        getCoordinateFrom(address: address) { coordinate, error in
            guard let coordinate = coordinate, error == nil else { return }
            DispatchQueue.main.async {
                print(coordinate)
            }  
        }
    }

替换为：

  guard let coordinate = coordinate, error == nil else { return }
            DispatchQueue.main.async {
                print(coordinate)
            }

通过这个：

  guard let coordinate = coordinate, error == nil else { return }
            coordinates.latitude = coordinate.latitude
            coordinates.longitude = coordinate.longitude
            DispatchQueue.main.async {
                print(coordinate)
            }

这就是您的坐标变量将如何更新为新的经纬度

Return CLLocationCoordinate2D 结构

Return CLLocationCoordinate2D to struct

ios

swift

coordinates

clgeocoder

cllocationcoordinate2d