启用和停用地图手势

只有在该开关处于开启状态时，地图才会对缩放手势做出响应。

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

class GestureControlViewController: UIViewController {
  private let holderHeight: CGFloat = 60
  private let zoomLabelInset: CGFloat = 16

  private lazy var mapView: GMSMapView = {
    let camera = GMSCameraPosition(latitude: -25.5605, longitude: 133.605097, zoom: 3)
    return GMSMapView(frame: .zero, camera: camera)
  }()
  private lazy var zoomSwitch: UISwitch = UISwitch(frame: .zero)

  override func viewDidLoad() {
    super.viewDidLoad()

    view.addSubview(mapView)

    let holder = UIView(frame: .zero)
    holder.backgroundColor = UIColor(white: 1, alpha: 0.8)
    view.addSubview(holder)

    let zoomLabel = UILabel(frame: .zero)
    zoomLabel.text = "Zoom gestures"
    zoomLabel.font = .boldSystemFont(ofSize: 18)
    holder.addSubview(zoomLabel)

    // Control zooming.
    holder.addSubview(zoomSwitch)
    zoomSwitch.addTarget(self, action: #selector(toggleZoom), for: .valueChanged)
    zoomSwitch.isOn = true

    [mapView, holder, zoomLabel, zoomSwitch].forEach({
      $0.translatesAutoresizingMaskIntoConstraints = false
    })
    NSLayoutConstraint.activate([
      mapView.leftAnchor.constraint(equalTo: view.leftAnchor),
      mapView.rightAnchor.constraint(equalTo: view.rightAnchor),
      mapView.topAnchor.constraint(equalTo: view.topAnchor),
      mapView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
      holder.heightAnchor.constraint(equalToConstant: holderHeight),
      holder.centerXAnchor.constraint(equalTo: view.centerXAnchor),
      holder.widthAnchor.constraint(equalTo: view.widthAnchor),
      zoomLabel.leftAnchor.constraint(equalTo: holder.leftAnchor, constant: zoomLabelInset),
      zoomLabel.centerYAnchor.constraint(equalTo: holder.centerYAnchor),
      zoomSwitch.rightAnchor.constraint(equalTo: holder.rightAnchor, constant: -zoomLabelInset),
      zoomSwitch.centerYAnchor.constraint(
        equalTo: holder.centerYAnchor),
    ])
    NSLayoutConstraint.activate([
      holder.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor)
    ])
  }

  @objc func toggleZoom() {
    mapView.settings.zoomGestures = zoomSwitch.isOn
  }

}
GestureControlViewController.swift
      

Objective-C

#import "GoogleMapsDemos/Samples/GestureControlViewController.h"

#import <GoogleMaps/GoogleMaps.h>

@implementation GestureControlViewController {
  GMSMapView *_mapView;
  UISwitch *_zoomSwitch;
}

- (void)viewDidLoad {
  [super viewDidLoad];
  GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-25.5605
                                                          longitude:133.605097
                                                               zoom:3];

  _mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];
  _mapView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
  _mapView.accessibilityIdentifier = @"gestureControlDemoMapView";

  self.view = [[UIView alloc] initWithFrame:CGRectZero];
  [self.view addSubview:_mapView];

  UIView *holder = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 59)];
  holder.autoresizingMask =
      UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin;
  holder.backgroundColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.8f];
  [self.view addSubview:holder];

  // Zoom label.
  UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(16, 16, 200, 29)];
  label.text = @"Zooming?";
  label.font = [UIFont boldSystemFontOfSize:18.0f];
  label.textAlignment = NSTextAlignmentLeft;
  label.backgroundColor = [UIColor clearColor];
  label.layer.shadowColor = [[UIColor whiteColor] CGColor];
  label.layer.shadowOffset = CGSizeMake(0.0f, 1.0f);
  label.layer.shadowOpacity = 1.0f;
  label.layer.shadowRadius = 0.0f;
  [holder addSubview:label];

  // Control zooming.
  _zoomSwitch = [[UISwitch alloc] initWithFrame:CGRectMake(-90, 16, 0, 0)];
  _zoomSwitch.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin;
  [_zoomSwitch addTarget:self
                  action:@selector(didChangeZoomSwitch)
        forControlEvents:UIControlEventValueChanged];
  _zoomSwitch.on = YES;
  [holder addSubview:_zoomSwitch];
}

- (void)didChangeZoomSwitch {
  _mapView.settings.zoomGestures = _zoomSwitch.isOn;
}

@end
GestureControlViewController.m
      

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，导航到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，按下“编译”按钮，使用当前方案构建应用。构建会产生错误，提示您在 Swift 的 SDKConstants.swift 文件或 Objective-C 的 SDKDemoAPIKey.h 文件中输入 API 密钥。
4. 从已启用 Maps SDK for iOS 的项目中获取 API 密钥。
5. 针对 Swift 修改 SDKConstants.swift 文件，针对 Objective-C 修改 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。系统随即会显示 iOS 模拟器窗口，其中列出了 Maps SDK 演示版。
8. 选择显示的选项之一，以便试用 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。