对位置进行反向地理编码

长按地图时,系统会将手势的坐标发送到反向地理编码服务。如果成功,系统会在地图中添加一个包含结果信息窗口的标记。

开始使用

您必须先配置开发环境,然后才能试用该示例代码。如需了解详情,请参阅 Maps SDK for iOS 代码示例

查看代码

Swift

import GoogleMaps
import UIKit

// Sample code for GeoCoder service.
class GeocoderViewController: UIViewController {

  private lazy var mapView: GMSMapView = {
    let camera = GMSCameraPosition(latitude: -33.868, longitude: 151.2086, zoom: 12)
    return GMSMapView(frame: .zero, camera: camera)
  }()

  private lazy var geocoder = GMSGeocoder()

  override func loadView() {
    view = mapView
    mapView.delegate = self
  }
}

extension GeocoderViewController: GMSMapViewDelegate {
  func mapView(_ mapView: GMSMapView, didLongPressAt coordinate: CLLocationCoordinate2D) {
    // On a long press, reverse geocode this location.
    geocoder.reverseGeocodeCoordinate(coordinate) { response, error in
      guard let address = response?.firstResult() else {
        let errorMessage = error.map { String(describing: $0) } ?? "<no error>"
        print(
          "Could not reverse geocode point (\(coordinate.latitude), \(coordinate.longitude)): \(errorMessage)"
        )
        return
      }
      print("Geocoder result: \(address)")
      let marker = GMSMarker(position: address.coordinate)
      marker.appearAnimation = .pop
      marker.map = mapView

      guard let lines = address.lines, let title = lines.first else { return }
      marker.title = title
      if lines.count > 1 {
        marker.snippet = lines[1]
      }
    }
  }
}
      

Objective-C

#import "GoogleMapsDemos/Samples/GeocoderViewController.h"

#import <GoogleMaps/GoogleMaps.h>

@implementation GeocoderViewController {
  GMSMapView *_mapView;
  GMSGeocoder *_geocoder;
}

- (void)viewDidLoad {
  [super viewDidLoad];
  GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-33.868
                                                          longitude:151.2086
                                                               zoom:12];

  _mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];
  _mapView.delegate = self;

  _geocoder = [[GMSGeocoder alloc] init];

  self.view = _mapView;
}

- (void)mapView:(GMSMapView *)mapView didLongPressAtCoordinate:(CLLocationCoordinate2D)coordinate {
  // On a long press, reverse geocode this location.
  __weak __typeof__(self) weakSelf = self;
  GMSReverseGeocodeCallback handler = ^(GMSReverseGeocodeResponse *response, NSError *error) {
    [weakSelf handleResponse:response coordinate:coordinate error:error];
  };
  [_geocoder reverseGeocodeCoordinate:coordinate completionHandler:handler];
}

- (void)handleResponse:(nullable GMSReverseGeocodeResponse *)response
            coordinate:(CLLocationCoordinate2D)coordinate
                 error:(nullable NSError *)error {
  GMSAddress *address = response.firstResult;
  if (address) {
    NSLog(@"Geocoder result: %@", address);

    GMSMarker *marker = [GMSMarker markerWithPosition:address.coordinate];
    NSArray<NSString *> *lines = [address lines];

    marker.title = [lines firstObject];
    if (lines.count > 1) {
      marker.snippet = [lines objectAtIndex:1];
    }

    marker.appearAnimation = kGMSMarkerAnimationPop;
    marker.map = _mapView;
  } else {
    NSLog(@"Could not reverse geocode point (%f,%f): %@", coordinate.latitude, coordinate.longitude,
          error);
  }
}

@end
      

在本地运行完整示例应用

Maps SDK for iOS 示例应用以 GitHub 上的下载归档文件的形式提供。请按照以下步骤安装并试用 Maps SDK for iOS 示例应用。

  1. 运行 git clone https://github.com/googlemaps-samples/maps-sdk-for-ios-samples.git 以将示例代码库克隆到本地目录。
  2. 打开一个终端窗口,前往您克隆示例文件的目录,然后展开 GoogleMaps 目录:

    Swift

    cd maps-sdk-for-ios-samples-main/GoogleMaps-Swift
    pod install
    open GoogleMapsSwiftDemos.xcworkspace

    Objective-C

    cd maps-sdk-for-ios-samples-main/GoogleMaps
    pod install
    open GoogleMapsDemos.xcworkspace
  3. 在 Xcode 中,按 compile 按钮使用当前架构构建应用。build 会产生错误,提示您在 SDKConstants.swift 文件中(对于 Swift)或 SDKDemoAPIKey.h 文件中输入 API 密钥(对于 Objective-C)。
  4. 如果您尚未获得 API 密钥,请按照说明在 Google Cloud 控制台中设置项目并获取 API 密钥。在 Cloud 控制台中配置密钥时,您可以将密钥限制为示例应用的软件包标识符,以确保只有您的应用可以使用该密钥。SDK 示例应用的默认 bundle 标识符为 com.example.GoogleMapsDemos
  5. 针对 Swift 编辑 SDKConstants.swift 文件,针对 Objective-C 编辑 SDKDemoAPIKey.h 文件,然后将您的 API 密钥粘贴到 apiKeykAPIKey 常量的定义中。例如:

    Swift

    static let apiKey = "YOUR_API_KEY"

    Objective-C

    static NSString *const kAPIKey = @"YOUR_API_KEY";
  6. SDKConstants.swift 文件 (Swift) 或 SDKDemoAPIKey.h 文件 (Objective-C) 中,移除以下行,因为它用于注册用户定义的问题:

    Swift

    #error (Register for API Key and insert here. Then delete this line.)

    Objective-C

    #error Register for API Key and insert here.
  7. 构建并运行项目。出现 iOS 模拟器窗口,显示 Maps SDK 演示应用列表。
  8. 从显示的选项中选择其一,对 Maps SDK for iOS 的其中一项功能进行试验。
  9. 如果系统提示您允许 GoogleMapsDemos 获取您的位置信息,请选择允许