反向地理编码在斯威夫特4

Question

我试图写一个简单的方法，喂了CLLocationDegrees并返回CLPlacemark。看着Apple's documentation，这看起来很简单。

下面是我所倾倒入一个游乐场：

import CoreLocation 
// this is necessary for async code in a playground 
import PlaygroundSupport 

// this is necessary for async code in a playground 
PlaygroundPage.current.needsIndefiniteExecution = true 

func geocode(latitude: CLLocationDegrees, longitude: CLLocationDegrees) -> CLPlacemark? { 
    let location = CLLocation(latitude: latitude, longitude: longitude) 
    let geocoder = CLGeocoder() 

    var placemark: CLPlacemark? 

    geocoder.reverseGeocodeLocation(location) { (placemarks, error) in 
    if error != nil { 
     print("something went horribly wrong") 
    } 

    if let placemarks = placemarks { 
     placemark = placemarks.first 
    } 
    } 

    return placemark 
} 

let myPlacemark = geocode(latitude: 37.3318, longitude: 122.0312) 

既然这样，我的方法是返回nil。我不知道我的错误在哪里，但我确信这是我的愚蠢行为。谢谢你的阅读。

Answer 1

import UIKit 
import CoreLocation 
import PlaygroundSupport 
PlaygroundPage.current.needsIndefiniteExecution = true 

func geocode(latitude: Double, longitude: Double, completion: @escaping (CLPlacemark?, Error?) ->()) { 
    CLGeocoder().reverseGeocodeLocation(CLLocation(latitude: latitude, longitude: longitude)) { placemarks, error in 
     guard let placemark = placemarks?.first, error == nil else { 
      completion(nil, error) 
      return 
     } 
     completion(placemark, nil) 
    } 
} 

---

用法：

geocode(latitude: -22.963451, longitude: -43.198242) { placemark, error in 
    guard let placemark = placemark, error == nil else { return } 
    // you should always update your UI in the main thread 
    DispatchQueue.main.async { 
     // update UI here 
     print("address1:", placemark.thoroughfare ?? "") 
     print("address2:", placemark.subThoroughfare ?? "") 
     print("city:",  placemark.locality ?? "") 
     print("state:", placemark.administrativeArea ?? "") 
     print("zip code:", placemark.postalCode ?? "") 
     print("country:", placemark.country ?? "")  
    } 
} 

---

有关标属性的更多信息，你可以检查此CLPlacemark

---

这将打印

address1: Rua Casuarina 
address2: 443 
city: Rio de Janeiro 
state: RJ 
zip code: 20975 
country: Brazil