Location tracking and monitoring have seen a surge in modern application development with various services such as Uber heavily relying on location services that require consistency and accuracy. With businesses and corporations requiring location information and monitoring of their various assets, delivering comprehensive location solutions has been a tricky science for many developers.

位置跟踪和监视已经见证了现代应用程序开发中的迅猛发展，其中各种服务(例如Uber)严重依赖于要求一致性和准确性的位置服务。 随着企业和公司需要位置信息并监视其各种资产，提供全面的位置解决方案对于许多开发人员而言是一门棘手的科学。

Identifying the growing demand for a convenient location providing service Google introduced the Fused Location Provider API. This article will focus on using the API to track a user’s real-time location using an android application and through the example demonstrate the beauty of the API.

为了确定对方便的位置提供服务不断增长的需求，Google引入了融合位置提供程序API。 本文将重点介绍如何使用Android应用程序使用API​​跟踪用户的实时位置，并通过示例演示API的优点。

The API focuses on providing location information using a combination of a device’s GPS, Wi-Fi and internal sensors. The main selling point is that it decides in what combination to use these three resources based on the request parameters provided. In this context managing these resources is abstracted from the developer.

该API致力于结合使用设备的GPS，Wi-Fi和内部传感器来提供位置信息。 主要卖点是，它根据提供的请求参数决定以哪种组合使用这三种资源。 在这种情况下，管理这些资源是从开发人员中提取的。

A simple use case to demonstrate the capacity of the API is tracking the movement of an individual walking towards a building, entering it and then leaving. In this scenario when the person is outdoors, the GPS service will function well. However, as he enters the building the GPS signal may drop. The Fused Location Provider handles the above scenario by tracking the location outdoors via GPS and when the GPS signal drops within the building, it utilizes Wi-Fi. During the switching process from GPS to Wi-Fi, to provide a smoother transition, the device’s internal sensors are used to predict the movement. In this manner, the management of available resources to provide reliable location services in a battery efficient manner is the true power of the API.

演示API功能的一个简单用例是跟踪一个人朝建筑物走去，进入建筑物然后离开的运动。 在这种情况下，当人在户外时，GPS服务将运行良好。 但是，当他进入建筑物时，GPS信号可能会下降。 融合位置提供器通过GPS跟踪室外位置，并在GPS信号掉入建筑物内时利用Wi-Fi处理上述情况。 在从GPS切换到Wi-Fi的过程中，为了提供更平稳的过渡，设备的内部传感器用于预测运动。 以这种方式，以电池高效方式提供可用的可靠位置服务的可用资源管理是API的真正力量。

Integrating the API into your android application is a simple process. In this example, we will walk through the necessary steps required to build a simple location tracking application.

将API集成到您的android应用程序中是一个简单的过程。 在此示例中，我们将逐步完成构建简单的位置跟踪应用程序所需的必要步骤。

First, create an android project in Android Studio and within the application’s build.gradle file, ensure the following dependency is present:

首先，在Android Studio中并在应用程序的build.gradle文件中创建一个android项目，确保存在以下依赖关系：

dependencies{   implementation ‘com.google.android.gms:play-services:11.8.0’}

Secondly, within the Manifest file you must provide either the Fine or Coarse location permission by adding the below snippet:

其次，在清单文件中，您必须通过添加以下代码段来提供“精细”或“粗糙”位置权限：

<uses-permission        android:name=”android.permission.ACCESS_FINE_LOCATION”/> <uses-permission android:name=”android.permission.ACCESS_COARSE_LOCATION”/>

Now, create instances of FusedLocationProviderClient, LocationRequest and LocationCallBack in your activity.

现在，创建FusedLocationProviderClient ， LocationRequest的实例 和LocationCallBack 在你的活动中。

private FusedLocationProviderClient fusedLocationClient;private LocationRequest locationRequest;private LocationCallback locationCallback;@Overrideprotected void onCreate(Bundle savedInstanceState) {      fusedLocationClient =       LocationServices.getFusedLocationProviderClient(this);   }}

The LocationRequest object is used to build a location request in accordance with parameters of our use case by providing details such as the update frequency, accuracy level and battery efficiency. Create a method to build the location request based on your desired parameters. An example is provided below:

通过提供诸如更新频率，准确性级别和电池效率之类的细节， LocationRequest对象用于根据我们用例的参数构建位置请求。 创建一种方法，以根据所需参数构建位置请求。 下面提供了一个示例：

private void buildLocationRequest() {locationRequest = new LocationRequest(); locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); locationRequest.setInterval(100);locationRequest.setFastestInterval(100); locationRequest.setSmallestDisplacement(1);}//Build the location callback object and obtain the location results //as demonstrated below:private void buildLocationCallBack() {  locationCallback = new LocationCallback() {    @Override    public void onLocationResult(LocationResult locationResult) {      for (Location location: locationResult.getLocations()){         String latitude = String.valueOf(location.getLatitude());         String longitude = String.valueOf(location.getLongitude());      }    }  };}

Once the locationRequest object and the locationCallBack objects are initialized, request location data by calling the FusedLocationProviderClient’s requestLocationUpdates method. Pass the locationRequest and locationCallback objects as parameters.

一旦locationRequest 对象和locationCallBack 通过调用FusedLocationProviderClient的requestLocationUpdates方法来初始化对象，请求位置数据。 将locationRequest和locationCallback对象作为参数传递。

FusedLocationProviderClient.requestLocationUpdates(   locationRequest,   locationCallback,   null);

Based on the parameters defined by the request the API will continue to provide relevant location information that can be utilized to perform numerous functions such as location monitoring and real time speed tracking.

基于请求定义的参数，API将继续提供相关的位置信息，这些位置信息可用于执行众多功能，例如位置监视和实时速度跟踪。

The Fused Location Provider API provides a convenient method to manage all underlying location technologies by abstracting their inner workings from the developer and providing high-level methods to specify the quality and accuracy of services required.

融合位置提供程序API通过从开发人员中提取其内部工作并提供高级方法来指定所需服务的质量和准确性，从而提供了一种方便的方法来管理所有基础位置技术。

What is explored here is merely a fraction of what the API provides, and Google has provided comprehensive documentation that can be used to build diverse and robust applications in the future. Follow the link below to get started:

本文所探讨的只是API提供的功能的一小部分，并且Google提供了全面的文档，可用于将来构建各种强大的应用程序。 请点击以下链接开始使用：

https://developers.google.com/location-context/fused-location-provider

https://developers.google.com/location-context/fused-location-provider