如何检索用户的当前城市名称？答案

【问题标题】：How to retrieve user's current city name?如何检索用户的当前城市名称？
【发布时间】：2010-11-25 20:33:18
【问题描述】：

如何检索用户当前的城市名称？

【问题讨论】：

【解决方案1】：

从 iOS 5 开始，MKReverseGeoCoder 已弃用！

所以您想将CLGeocoder 与CLLocationManager 一起使用，非常简单并且可以与块一起使用。

示例：

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation
{
   [self.locationManager stopUpdatingLocation];

   CLGeocoder * geoCoder = [[CLGeocoder alloc] init];
    [geoCoder reverseGeocodeLocation:newLocation
                   completionHandler:^(NSArray *placemarks, NSError *error) {
                       for (CLPlacemark *placemark in placemarks) {
                           .... = [placemark locality];
                       }
                   }];
}

编辑：除了for in 循环，您还可以这样做：

NSString *locString = placemarks.count ? [placemarks.firstObject locality] : @"Not Found";

【讨论】：

【解决方案2】：

您需要做的是设置一个CLLocationManager，它将找到您当前的坐标。使用当前坐标，您需要使用MKReverseGeoCoder 来查找您的位置。

- (void)viewDidLoad 
{  
    // this creates the CCLocationManager that will find your current location
    CLLocationManager *locationManager = [[[CLLocationManager alloc] init] autorelease];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
    [locationManager startUpdatingLocation];
}

// this delegate is called when the app successfully finds your current location
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{
    // this creates a MKReverseGeocoder to find a placemark using the found coordinates
    MKReverseGeocoder *geoCoder = [[MKReverseGeocoder alloc] initWithCoordinate:newLocation.coordinate];
    geoCoder.delegate = self;
    [geoCoder start];
}

// this delegate method is called if an error occurs in locating your current location
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error 
{
 NSLog(@"locationManager:%@ didFailWithError:%@", manager, error);
}

// this delegate is called when the reverseGeocoder finds a placemark
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark
{
    MKPlacemark * myPlacemark = placemark;
    // with the placemark you can now retrieve the city name
    NSString *city = [myPlacemark.addressDictionary objectForKey:(NSString*) kABPersonAddressCityKey];
}

// this delegate is called when the reversegeocoder fails to find a placemark
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFailWithError:(NSError *)error
{
    NSLog(@"reverseGeocoder:%@ didFailWithError:%@", geocoder, error);
}

【讨论】：

一个注意事项：您必须将位置管理器存储在 ivar 中（并且可能在收到位置后再次停止它），否则它将立即自动释放并且您不会收到任何委托回调。此外，反向地理编码器需要互联网连接才能工作。
你能告诉我如何在 Pin 的标题和副标题中打印当前城市或位置吗？？？
@Frade #import
MKReverseGeoCoder 自 ios 5.0 起已弃用
弗拉德，我希望你能说出你发现的……叹息

【解决方案3】：

这对我来说很好用：

CLGeocoder *geocoder = [[CLGeocoder alloc] init] ;
[geocoder reverseGeocodeLocation:self.locationManager.location
               completionHandler:^(NSArray *placemarks, NSError *error) {
                   NSLog(@"reverseGeocodeLocation:completionHandler: Completion Handler called!");

                   if (error){
                       NSLog(@"Geocode failed with error: %@", error);
                       return;

                   }


                   CLPlacemark *placemark = [placemarks objectAtIndex:0];

                   NSLog(@"placemark.ISOcountryCode %@",placemark.ISOcountryCode);
                   NSLog(@"placemark.country %@",placemark.country);
                   NSLog(@"placemark.postalCode %@",placemark.postalCode);
                   NSLog(@"placemark.administrativeArea %@",placemark.administrativeArea);
                   NSLog(@"placemark.locality %@",placemark.locality);
                   NSLog(@"placemark.subLocality %@",placemark.subLocality);
                   NSLog(@"placemark.subThoroughfare %@",placemark.subThoroughfare);

               }];

【讨论】：

为什么会返回一个数组？奇怪的。还是谢谢。
这很漂亮，爱块。我会在 placemarks 数组上设置一个条件，以确保 objectatindex:0 确实存在。
你好我收到一个错误kCLErrorDomain error 8你知道为什么吗？
CLGeoCoder 未声明我必须做什么，因此它可能会导入什么以及添加什么

【解决方案4】：

如果有人试图从 MKReverseGeocoder 迁移到 CLGeocoder，那么我写了一篇博文，可能会有所帮助 http://jonathanfield.me/jons-blog/clgeocoder-example.html

基本上一个例子是，在您创建 locationManager 和 CLGeocoder 对象之后，只需将此代码添加到您的 viewDidLoad() 中，然后制作一些标签或文本区域来显示数据。

  [super viewDidLoad];
    locationManager.delegate = self;
    [locationManager startUpdatingLocation];

    locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    [self.CLGeocoder reverseGeocodeLocation: locationManager.location completionHandler: 
     ^(NSArray *placemarks, NSError *error) {


         CLPlacemark *placemark = [placemarks objectAtIndex:0];


             isoCountryCode.text = placemark.ISOcountryCode;
             country.text = placemark.country;
             postalCode.text= placemark.postalCode;
             adminArea.text=placemark.administrativeArea;
             subAdminArea.text=placemark.subAdministrativeArea;
             locality.text=placemark.locality;
             subLocality.text=placemark.subLocality;
             thoroughfare.text=placemark.thoroughfare;
             subThoroughfare.text=placemark.subThoroughfare;
             //region.text=placemark.region;



     }];

【讨论】：

@macayer 是的，如果为空，会崩溃，但如果我理解正确，则永远不会为空。将包含 1 个或多个元素或者是 nil，发送到 nil 的消息会导致 nil，以及通过点符号通过 nil 进行的属性访问。话虽如此，应该始终检查error 是否非nil。

【解决方案5】：

设置 CLLocationManager 后，您会以纬度/经度对的形式获取位置更新。然后您可以使用 CLGeocoder 将坐标转换为用户友好的地名。

这是 Swift 4 中的示例代码。

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    if let lastLocation = locations.last {
        let geocoder = CLGeocoder()

        geocoder.reverseGeocodeLocation(lastLocation) { [weak self] (placemarks, error) in
            if error == nil {
                if let firstLocation = placemarks?[0],
                    let cityName = firstLocation.locality { // get the city name
                    self?.locationManager.stopUpdatingLocation()
                }
            }
        }
    }
}

【讨论】：

【解决方案6】：

如果有人在 Swift 3 中需要它，我就是这样做的：

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

    let location = locations.first!
    let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate, 500, 500)

    self.location = location
    self.locationManager?.stopUpdatingLocation()

    // Drop a pin at user's Current Location
    let myAnnotation: MKPointAnnotation = CustomPointAnnotation()
    myAnnotation.coordinate = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)
    myAnnotation.title = "Localização"
    self.mapViewMK.addAnnotation(myAnnotation)

    self.mapViewMK.setRegion(coordinateRegion, animated: true)
    self.locationManager?.stopUpdatingLocation()
    self.locationManager = nil

    // Get user's current location name
    let geocoder = CLGeocoder()
    geocoder.reverseGeocodeLocation(self.location!) { (placemarksArray, error) in

        if (placemarksArray?.count)! > 0 {

            let placemark = placemarksArray?.first
            let number = placemark!.subThoroughfare
            let bairro = placemark!.subLocality
            let street = placemark!.thoroughfare

            self.addressLabel.text = "\(street!), \(number!) - \(bairro!)"
        }
    }
}

【讨论】：

【解决方案7】：

您必须获取用户的当前位置，然后使用 MKReverseGeocoder 来识别城市。

iPhone App Programming Guide 第 8 章中有一个很好的例子。获得位置初始化地理编码器后，设置委托并从地标读取国家/地区。阅读 MKReverseGeocodeDelegate 的文档并创建方法：

reverseGeocoder:didFindPlacemark:

reverseGeocoder:didFailWithError:

MKReverseGeocoder *geocoder = [[MKReverseGeocoder alloc] initWithCoordinate:newLocation.coordinate];
geocoder.delegate = self;
[geocoder start];

【讨论】：

【解决方案8】：

您可以使用此代码获取当前城市：--

扩展 YourController: CLLocationManagerDelegate { func locationManager（经理：CLLocationManager，didUpdateLocations 位置：[CLLocation]） {

    CLGeocoder().reverseGeocodeLocation(manager.location!, completionHandler: {(placemarks, error)->Void in

        if (error != nil)
        {
            manager.stopUpdatingLocation()
            return
        }
        else
        {
            if placemarks!.count > 0
            {
                let placeMarksArrray: NSArray = placemarks!
                let pm = placeMarksArrray[0] as! CLPlacemark
                self.displayLocationInfo(pm)
                manager.stopUpdatingLocation()
            } else
            {
                print("Problem with the data received from geocoder")
            }
        }
    })
}

func displayLocationInfo(placemark: CLPlacemark!) {
    if (placemark != nil) {
        //stop updating location to save battery life
        locationLocation.stopUpdatingLocation()
        var tempString : String = ""
        if(placemark.locality != nil){
            tempString = tempString +  placemark.locality! + " "
            print(placemark.locality)
        }
        if(placemark.postalCode != nil){
            tempString = tempString +  placemark.postalCode! + " "
            print(placemark.postalCode)
        }
        if(placemark.administrativeArea != nil){
            tempString = tempString +  placemark.administrativeArea! + " "
            print(placemark.administrativeArea)
        }
        if(placemark.country != nil){
            tempString = tempString +  placemark.country! + " "



        }
        let dictForaddress = placemark.addressDictionary as! NSDictionary


        if let city = dictForaddress["City"] {
            print(city)



        }
        strLocation = tempString
    }
}

【讨论】：

【解决方案9】：

这是我的小型 Swift 类，它帮助我获取有关当前位置的反向地理编码信息。不要忘记Info.plist 中的NSLocationWhenInUseUsageDescription 字段。

class CurrentPlacemarkUpdater: NSObject, CLLocationManagerDelegate {

    private let locationManager = CLLocationManager()
    private let geocoder = CLGeocoder()

    private(set) var latestPlacemark: CLPlacemark?
    var onLatestPlacemarkUpdate: (() -> ())?
    var shouldStopOnUpdate: Bool = true

    func start() {
        locationManager.requestWhenInUseAuthorization()
        locationManager.desiredAccuracy = kCLLocationAccuracyKilometer
        locationManager.delegate = self
        locationManager.startUpdatingLocation()
    }

    func stop() {
        locationManager.stopUpdatingLocation()
    }

    fileprivate func updatePlacemark(for location: CLLocation) {
        geocoder.reverseGeocodeLocation(location) { [weak self] placemarks, error in
            if let placemark = placemarks?.first {
                self?.latestPlacemark = placemark
                self?.onLatestPlacemarkUpdate?()
                if self?.shouldStopOnUpdate ?? false {
                    self?.stop()
                }
            }
        }
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        if let location = locations.last {
            updatePlacemark(for: location)
        }
    }

    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print("CurrentPlacemarkUpdater: \(error)")
    }

}

【讨论】：

【解决方案10】：

// place the function code below in desire location in program.

// [self getCurrentLocation];



-(void)getCurrentLocation
{
    CLGeocoder *geocoder = [[CLGeocoder alloc] init] ;
    [geocoder reverseGeocodeLocation:self->locationManager.location
                   completionHandler:^(NSArray *placemarks, NSError *error) {
                       NSLog(@"reverseGeocodeLocation:completionHandler: Completion Handler called!");

                       if (error){
                           NSLog(@"Geocode failed with error: %@", error);
                           return;

                       }


                       CLPlacemark *placemark = [placemarks objectAtIndex:0];

                       NSLog(@"placemark.ISOcountryCode %@",placemark.ISOcountryCode);
                       NSLog(@"placemark.country %@",placemark.country);
                        NSLog(@"placemark.locality %@",placemark.locality );
                       NSLog(@"placemark.postalCode %@",placemark.postalCode);
                       NSLog(@"placemark.administrativeArea %@",placemark.administrativeArea);
                       NSLog(@"placemark.locality %@",placemark.locality);
                       NSLog(@"placemark.subLocality %@",placemark.subLocality);
                       NSLog(@"placemark.subThoroughfare %@",placemark.subThoroughfare);

                   }];
}

【讨论】：

【解决方案11】：

阅读MKReverseGeocoder 的文档——Apple 提供文档、指南和示例应用程序是有原因的。

【讨论】：

MKReverseGeoCoder 已弃用