跟踪车辆

本部分介绍了如何使用 JavaScript 车队跟踪库跟踪车辆，以便提供按需行程或安排任务。

如需跟踪车辆，请按以下步骤操作：

  1. 加载库并初始化地图视图
  2. 提供车辆位置信息和地图视图
  3. 监听事件和处理错误
  4. 停止跟踪

加载库并初始化地图视图

如需在网页中的地图上显示您的车队运营情况，请使用使用 API 密钥调用地图的脚本。以下示例展示了如何通过 HTML 执行此操作：

  • 网址来源：调用 Google 地图 API 以使用您的 API 密钥请求地图。

  • callback 参数：在 API 返回调用后运行 initMap 函数。

  • libraries 参数：用于加载车队跟踪库。

  • defer 属性：允许浏览器在 API 加载的同时继续渲染网页的其余部分。

    <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=journeySharing" defer></script>

提供车辆位置和地图视图

如需开始跟踪车辆，您需要实例化车辆位置信息提供程序，并使用车辆 ID 初始化地图视图，如以下部分所述。

实例化车辆位置信息提供程序

JavaScript 车队跟踪库包含适用于 Fleet Engine API 的位置信息提供程序。使用您的项目 ID 和对令牌提取器的引用来实例化它，如以下示例所示。

按需行程

JavaScript

locationProvider =
    new google.maps.journeySharing
        .FleetEngineVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // vehicleId to immediately start
          // tracking.
          vehicleId: 'your-vehicle-id',
});

TypeScript

locationProvider =
    new google.maps.journeySharing
        .FleetEngineVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // vehicleId to immediately start
          // tracking.
          vehicleId: 'your-vehicle-id',
});

计划任务

JavaScript

locationProvider =
    new google.maps.journeySharing
        .FleetEngineDeliveryVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // deliveryVehicleId to immediately start
          // tracking.
          deliveryVehicleId: 'your-delivery-id',
});

TypeScript

locationProvider =
    new google.maps.journeySharing
        .FleetEngineDeliveryVehicleLocationProvider({
          projectId,
          authTokenFetcher,

          // Optionally, you may specify
          // deliveryVehicleId to immediately start
          // tracking.
          deliveryVehicleId: 'your-delivery-id',
});

初始化地图视图

加载 JavaScript 历程共享库后，初始化地图视图并将其添加到 HTML 页面。您的网页应包含一个用于容纳地图视图的 <div> 元素。在以下示例中，<div> 元素名为 map_canvas。=

按需行程

JavaScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.vehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

TypeScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.VehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

计划任务

JavaScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

TypeScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

监听事件和处理错误

开始跟踪车辆后，您希望在地图上更新其进度，并在车辆沿着路线行驶时处理错误。

监听车辆事件

如需跟踪按需行程或预定任务的车辆进度，您需要监听更改事件。

您可以使用位置信息提供程序从 vehicle 或 deliveryVehicle 对象检索元数据。元信息包括预计到达时间和车辆下次上车点或下车点之前的剩余距离。对元信息所做的更改会触发位置信息提供程序中的更新事件。

以下示例展示了如何监听这些更改事件。

按需行程

JavaScript

locationProvider.addListener('update', e => {
  // e.vehicle contains data that may be
  // useful to the rest of the UI.
  if (e.vehicle) {
    console.log(e.vehicle.vehicleState);
  }
});

TypeScript

locationProvider.addListener('update',
    (e: google.maps.journeySharing.FleetEngineVehicleLocationProviderUpdateEvent) => {
  // e.vehicle contains data that may be
  // useful to the rest of the UI.
  if (e.vehicle) {
    console.log(e.vehicle.vehicleState);
  }
});

计划任务

JavaScript

locationProvider.addListener('update', e => {
  // e.deliveryVehicle contains data that may be
  // useful to the rest of the UI.
  if (e.deliveryVehicle) {
    console.log(e.deliveryVehicle.remainingDuration);
  }
});

TypeScript

locationProvider.addListener('update',
    (e: google.maps.journeySharing.FleetEngineDeliveryVehicleLocationProviderUpdateEvent) => {
  // e.deliveryVehicle contains data that may be
  // useful to the rest of the UI.
  if (e.deliveryVehicle) {
    console.log(e.deliveryVehicle.remainingDuration);
  }
});

处理错误

加载 JavaScript 历程共享库后，初始化地图视图并将其添加到 HTML 页面。您的网页应包含一个用于容纳地图视图的 <div> 元素。在以下示例中，<div> 元素名为 map_canvas。=

按需行程

JavaScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.vehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

TypeScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.VehicleId
                        = 'your-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

计划任务

JavaScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

TypeScript

const mapView = new
    google.maps.journeySharing.JourneySharingMapView({
  element: document.getElementById('map_canvas'),
  locationProviders: [locationProvider],
});

// If you did not specify a delivery vehicle ID in the
// location provider constructor, you may do so here.
// Location tracking will start as soon as this is set.
locationProvider.deliveryVehicleId
                        = 'your-delivery-vehicle-id';

// Give the map an initial viewport to allow it to
// initialize; otherwise the 'ready' event above may
// not fire. The user also has access to the mapView
// object to customize as they want.
mapView.map.setCenter('Times Square, New York, NY');
mapView.map.setZoom(14);

停止跟踪车辆

如需停止跟踪车辆，您需要将其从位置信息提供程序中移除，并将位置信息提供程序从地图视图中移除，如以下部分所述。此处的示例适用于按需行程和安排的任务实现。

从位置信息提供程序中移除车辆

如需停止位置信息提供程序跟踪车辆，请从位置信息提供程序中移除配送车辆 ID。

按需行程

JavaScript

locationProvider.vehicleId = '';

TypeScript

locationProvider.vehicleId = '';

计划任务

JavaScript

locationProvider.deliveryVehicleId = '';

TypeScript

locationProvider.deliveryVehicleId = '';

从地图视图中移除位置信息提供程序

以下示例展示了如何从地图视图中移除位置信息提供程序。

JavaScript

mapView.removeLocationProvider(locationProvider);

TypeScript

mapView.removeLocationProvider(locationProvider);

后续步骤