后台定位服务

Question

我正在寻找一种解决方案来获取具有纬度、经度和速度参数的设备的位置。解决方案应该适用于 Android OS 8 和更低版本。

Answer 1

Fused Location Provider用于在 Android 中获取位置。

这是使用后台服务使用 Fused Location Provider 获取连续位置的分步过程。

1）在gradle中添加定位服务API。

implementation 'com.google.android.gms:play-services-location:16.0.0'

2）声明所有必要的许可 AndroidMenifest.xml

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

android.permission.ACCESS_COARSE_LOCATION和android.permission.ACCESS_FINE_LOCATION用于获取设备的位置。

android.permission.FOREGROUND_SERVICE用于在Android 9.0 中运行服务

3）创建LocationService以获取继续位置。

import android.Manifest;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Build;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Looper;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.NotificationCompat;
import android.util.Log;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.tasks.OnSuccessListener;

public class LocationService extends Service implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener {

    public static final String TAG = LocationService.class.getSimpleName();
    private static final long LOCATION_REQUEST_INTERVAL = 10000;
    private static final float LOCATION_REQUEST_DISPLACEMENT = 5.0f;
    private GoogleApiClient mGoogleApiClient;
    private FusedLocationProviderClient mFusedLocationProviderClient;
    private LocationRequest mLocationRequest;
    private LocationCallback mLocationCallback;

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        buildGoogleApiClient();
        showNotificationAndStartForegroundService();

        mLocationCallback = new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                super.onLocationResult(locationResult);
                //here you get the continues location updated based on the interval defined in
                //location request
            }
        };
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        mFusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
        return START_STICKY;
    }

    /**
     * Method used for building GoogleApiClient and add connection callback
     */
    private synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .build();

        mGoogleApiClient.connect();
    }

    /**
     * Method used for creating location request
     * After successfully connection of the GoogleClient ,
     * This method used for to request continues location
     */
    private void createLocationRequest() {
        mLocationRequest = LocationRequest.create();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setInterval(LOCATION_REQUEST_INTERVAL);
        mLocationRequest.setSmallestDisplacement(LOCATION_REQUEST_DISPLACEMENT);

        requestLocationUpdate();
    }

    /**
     * Method used for the request new location using Google FusedLocation Api
     */
    private void requestLocationUpdate() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED &&
                ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
                        != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        mFusedLocationProviderClient.getLastLocation().addOnSuccessListener(new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                //get the last location of the device
            }
        });

        mFusedLocationProviderClient.requestLocationUpdates(mLocationRequest, mLocationCallback,
                Looper.myLooper());
    }

    private void removeLocationUpdate() {
        mFusedLocationProviderClient.removeLocationUpdates(mLocationCallback);
    }

    /**
     * This Method shows notification for ForegroundService
     * Start Foreground Service and Show Notification to user for android all version
     */
    private void showNotificationAndStartForegroundService() {

        final String CHANNEL_ID = BuildConfig.APPLICATION_ID.concat("_notification_id");
        final String CHANNEL_NAME = BuildConfig.APPLICATION_ID.concat("_notification_name");
        final int NOTIFICATION_ID = 100;

        NotificationCompat.Builder builder;
        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            int importance = NotificationManager.IMPORTANCE_NONE;
            assert notificationManager != null;
            NotificationChannel mChannel = notificationManager.getNotificationChannel(CHANNEL_ID);
            if (mChannel == null) {
                mChannel = new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, importance);
                notificationManager.createNotificationChannel(mChannel);
            }
            builder = new NotificationCompat.Builder(this, CHANNEL_ID);
            builder.setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle(getString(R.string.app_name));
            startForeground(NOTIFICATION_ID, builder.build());
        } else {
            builder = new NotificationCompat.Builder(this, CHANNEL_ID);
            builder.setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle(getString(R.string.app_name));
            startForeground(NOTIFICATION_ID, builder.build());
        }
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {
        Log.d(TAG, "GoogleApi Client Connected");
        createLocationRequest();
    }

    @Override
    public void onConnectionSuspended(int i) {
        Log.d(TAG, "GoogleApi Client Suspended");
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        Log.d(TAG, "GoogleApi Client Failed");
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        removeLocationUpdate();
        if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }
}

在LocationService第一，你必须建立GoogleApiClient使用Fushed位置提供者请求新的位置后，

在这里，您可以mLocationCallback根据 中提供的间隔获得 中的新位置mLocationRequest。

4）声明服务 AndroidMenifest.xml

<service
     android:name=".LocationService"
     android:exported="false" />

5）现在从活动开始服务

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
     startForegroundService(new Intent(this, LocationService.class));
else
     startService(new Intent(this, LocationService.class));