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 final class PolylinesViewController: UIViewController { private lazy var styles: [GMSStrokeStyle] = { let greenStyle = GMSStrokeStyle.gradient(from: .green, to: UIColor.green.withAlphaComponent(0)) let redStyle = GMSStrokeStyle.gradient(from: UIColor.red.withAlphaComponent(0), to: .red) return [greenStyle, redStyle, GMSStrokeStyle.solidColor(UIColor(white: 0, alpha: 0))] }() private var pathLength: Double = 0 private var pos: Double = 0 private var polylines: [GMSPolyline] = [] private lazy var mapView: GMSMapView = { let camera = GMSCameraPosition(latitude: -30, longitude: -175, zoom: 3) return GMSMapView(frame: .zero, camera: camera) }() override func loadView() { view = mapView mapView.accessibilityElementsHidden = true } override func viewDidLoad() { super.viewDidLoad() var path = GMSMutablePath() path.addLatitude(-33.866901, longitude: 151.195988) path.addLatitude(-18, longitude: 179) path.addLatitude(21.291982, longitude: -157.821856) path.addLatitude(37.423802, longitude: -122.091859) path.addLatitude(-12, longitude: -77) path.addLatitude(-33.866901, longitude: 151.195988) path = path.pathOffset(byLatitude: -30, longitude: 0) pathLength = path.length(of: .geodesic) / 21 for i in 0..<30 { let polyline = GMSPolyline(path: path.pathOffset(byLatitude: Double(i) * 1.5, longitude: 0)) polyline.strokeWidth = 8 polyline.geodesic = true polyline.map = mapView polylines.append(polyline) } animatePath() } // Updates the path style every 0.1 seconds. private func animatePath() { polylines.forEach { if let path = $0.path { $0.spans = GMSStyleSpansOffset(path, styles, [NSNumber(value: pathLength)], .geodesic, pos) } } pos -= 50000 DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 0.1) { self.animatePath() } } }
Objective-C
#import "GoogleMapsDemos/Samples/PolylinesViewController.h" #import <GoogleMaps/GoogleMaps.h> static CLLocationCoordinate2D kSydneyAustralia = {-33.866901, 151.195988}; static CLLocationCoordinate2D kHawaiiUSA = {21.291982, -157.821856}; static CLLocationCoordinate2D kFiji = {-18, 179}; static CLLocationCoordinate2D kMountainViewUSA = {37.423802, -122.091859}; static CLLocationCoordinate2D kLimaPeru = {-12, -77}; static bool kAnimate = true; @implementation PolylinesViewController { NSArray *_styles; NSArray *_lengths; NSArray *_polys; double _pos, _step; GMSMapView *_mapView; } - (void)tick { for (GMSPolyline *poly in _polys) { poly.spans = GMSStyleSpansOffset(poly.path, _styles, _lengths, kGMSLengthGeodesic, _pos); } _pos -= _step; if (kAnimate) { __weak id weakSelf = self; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC / 10), dispatch_get_main_queue(), ^{ [weakSelf tick]; }); } } - (void)initLines { if (!_polys) { NSMutableArray *polys = [NSMutableArray array]; GMSMutablePath *path = [GMSMutablePath path]; [path addCoordinate:kSydneyAustralia]; [path addCoordinate:kFiji]; [path addCoordinate:kHawaiiUSA]; [path addCoordinate:kMountainViewUSA]; [path addCoordinate:kLimaPeru]; [path addCoordinate:kSydneyAustralia]; path = [path pathOffsetByLatitude:-30 longitude:0]; _lengths = @[ @([path lengthOfKind:kGMSLengthGeodesic] / 21) ]; for (int i = 0; i < 30; ++i) { GMSPolyline *poly = [[GMSPolyline alloc] init]; poly.path = [path pathOffsetByLatitude:(i * 1.5) longitude:0]; poly.strokeWidth = 8; poly.geodesic = YES; poly.map = _mapView; [polys addObject:poly]; } _polys = polys; } } - (void)viewDidLoad { [super viewDidLoad]; GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-30 longitude:-175 zoom:3]; GMSMapView *mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera]; mapView.accessibilityElementsHidden = YES; self.view = mapView; _mapView = mapView; CGFloat alpha = 1; UIColor *green = [UIColor colorWithRed:0 green:1 blue:0 alpha:alpha]; UIColor *greenTransp = [UIColor colorWithRed:0 green:1 blue:0 alpha:0]; UIColor *red = [UIColor colorWithRed:1 green:0 blue:0 alpha:alpha]; UIColor *redTransp = [UIColor colorWithRed:1 green:0 blue:0 alpha:0]; GMSStrokeStyle *grad1 = [GMSStrokeStyle gradientFromColor:green toColor:greenTransp]; GMSStrokeStyle *grad2 = [GMSStrokeStyle gradientFromColor:redTransp toColor:red]; _styles = @[ grad1, grad2, [GMSStrokeStyle solidColor:[UIColor colorWithWhite:0 alpha:0]], ]; _step = 50000; [self initLines]; [self tick]; } @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。
- 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。 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 installopen GoogleMapsSwiftDemos.xcworkspaceObjective-C
cd maps-sdk-for-ios-samples-main/GoogleMaps
pod installopen GoogleMapsDemos.xcworkspace- 在 Xcode 中，按编译按钮以使用当前架构构建应用。构建引发错误，提示您在 Swift 的
SDKConstants.swift文件或 Objective-C 的SDKDemoAPIKey.h文件中输入 API 密钥。 - 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。 - 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";
- 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.
- 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。
- 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。
- 如果系统提示您允许 GoogleMapsDemos 获取您的位置信息，请选择允许。