我正在尝试编写一个简单的方法，该方法提供 CLLocationDegrees 并返回一个 CLPlacemark。看着Apple's documentation ，这似乎是一项简单的任务。

下面是我扔进 Playground 的东西:

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)

就目前而言，我的方法返回 nil。我不确定我的错误在哪里，但我确信这对我来说是非常愚蠢的事情。感谢您的阅读。

最佳答案

CLGeocoder 方法是异步的。您需要一个完成处理程序:

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

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

或者简单地说:

func geocode(latitude: Double, longitude: Double, completion: @escaping (_ placemark: [CLPlacemark]?, _ error: Error?) -> Void)  {
    CLGeocoder().reverseGeocodeLocation(CLLocation(latitude: latitude, longitude: longitude), completionHandler: completion)
}

或扩展 CLLocation:

extension CLLocation {
    func geocode(completion: @escaping (_ placemark: [CLPlacemark]?, _ error: Error?) -> Void) {
        CLGeocoder().reverseGeocodeLocation(self, completionHandler: completion)
    }
}

要将地标格式化为邮寄地址，您可以使用联系人框架 CNPostalAddressFormatter:

import Contacts

extension Formatter {
    static let mailingAddress: CNPostalAddressFormatter = {
        let formatter = CNPostalAddressFormatter()
        formatter.style = .mailingAddress
        return formatter
    }()
}

extension CLPlacemark {
    var mailingAddress: String? {
        postalAddress?.mailingAddress
    }
}

extension CNPostalAddress {
    var mailingAddress: String {
        Formatter.mailingAddress.string(from: self)
    }
}

placemark

Contains an array of CLPlacemark objects. For most geocoding requests, this array should contain only one entry. However, forward-geocoding requests may return multiple placemark objects in situations where the specified address could not be resolved to a single location. If the request was canceled or there was an error in obtaining the placemark information, this parameter is nil.

有关 CLPlacemark 属性的更多信息，您可以查看此 CLPlacemark

用法:

let location = CLLocation(latitude: -22.963451, longitude: -43.198242)
location.geocode { placemark, error in
    if let error = error as? CLError {
        print("CLError:", error)
        return
    } else if let placemark = placemark?.first {
        // you should always update your UI in the main thread
        DispatchQueue.main.async {
            //  update UI here
            print("name:", placemark.name ?? "unknown")
            
            print("address1:", placemark.thoroughfare ?? "unknown")
            print("address2:", placemark.subThoroughfare ?? "unknown")
            print("neighborhood:", placemark.subLocality ?? "unknown")
            print("city:", placemark.locality ?? "unknown")
            
            print("state:", placemark.administrativeArea ?? "unknown")
            print("subAdministrativeArea:", placemark.subAdministrativeArea ?? "unknown")
            print("zip code:", placemark.postalCode ?? "unknown")
            print("country:", placemark.country ?? "unknown", terminator: "\n\n")
            
            print("isoCountryCode:", placemark.isoCountryCode ?? "unknown")
            print("region identifier:", placemark.region?.identifier ?? "unknown")
    
            print("timezone:", placemark.timeZone ?? "unknown", terminator:"\n\n")

            // Mailind Address
            print(placemark.mailingAddress ?? "unknown")
        }
    }
}

这将打印

name: Morro da Saudade
address1: Rua Casuarina
address2: 597
neighborhood: Lagoa
city: Rio de Janeiro
state: RJ
subAdministrativeArea: unknown
zip code: 22011-040
country: Brazil

isoCountryCode: BR
region identifier: <-22.96345100,-43.19824200> radius 141.83
timezone: America/Sao_Paulo (current)

Rua Casuarina, 597
Lagoa
Rio de Janeiro RJ
22011-040
Brazil

关于ios - Swift 4 中的反向地理编码，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46869394/