对位置进行反向地理编码

欧洲经济区 (EEA) 开发者

  当用户长按地图时，手势的坐标会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的信息窗口标记。

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]
      }
    }
  }
}
GeocoderViewController.swift

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
GeocoderViewController.m

在本地运行完整示例应用

Maps SDK for iOS 示例应用可从 GitHub 下载为下载归档文件。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，将示例代码库克隆到本地目录中。

  2. 打开终端窗口，导航到克隆示例文件的目录，然后深入到 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，按编译按钮以使用当前方案构建应用。构建会产生错误，提示您在 SDKConstants.swift 文件（适用于 Swift）或 SDKDemoAPIKey.h 文件（适用于 Objective-C）中输入 API 密钥。
  4. 从已启用 Maps SDK for iOS 的项目中获取 API 密钥。
  5. 修改 Swift 的 SDKConstants.swift 文件或 Objective-C 的 SDKDemoAPIKey.h 文件，然后将您的 API 密钥粘贴到 apiKey 或 kAPIKey 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. 在 SDKConstants.swift 文件 (Swift) 或 SDKDemoAPIKey.h 文件 (Objective-C) 中，移除以下行，因为该行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。系统会显示 iOS 模拟器窗口，其中包含 Maps SDK 演示的列表。
  8. 选择显示的选项之一，以试用 Maps SDK for iOS 的某项功能。
  9. 如果系统提示您允许 GoogleMapsDemos 访问您的位置信息，请选择允许。