我已经使用 FusedLocationProviderClient 成功创建了一个活动，该活动将在特定时间段内返回位置坐标。
但是我希望它在后台服务中运行，该服务将坐标保存在本地数据库中并且永远不会结束，直到用户手动停止该服务为止。
这是我的源代码：
private String mLastUpdateTime;
private static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000;
private static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS = 5000;
private static final int REQUEST_CHECK_SETTINGS = 100;
private FusedLocationProviderClient mFusedLocationClient;
private SettingsClient mSettingsClient;
private LocationRequest mLocationRequest;
private LocationSettingsRequest mLocationSettingsRequest;
private LocationCallback mLocationCallback;
private Location mCurrentLocation;
private void init() {
mFusedLocationClient =
LocationServices.getFusedLocationProviderClient(this);
mSettingsClient = LocationServices.getSettingsClient(this);
mLocationCallback = new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
super.onLocationResult(locationResult);
// location is received
mCurrentLocation = locationResult.getLastLocation();
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
updateUIAndMarker();
}
};
mRequestingLocationUpdates = false;
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder();
builder.addLocationRequest(mLocationRequest);
mLocationSettingsRequest = builder.build();
}
答案 0 :(得分：3)
这是您的解决方案-
import android.app.ActivityManager;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.res.Configuration;
import android.location.Location;
import android.os.Binder;
import android.os.Build;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.Looper;
import android.support.annotation.NonNull;
import android.support.v4.app.NotificationCompat;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
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.OnCompleteListener;
import com.google.android.gms.tasks.Task;
/**
* A bound and started service that is promoted to a foreground service when location updates have
* been requested and all clients unbind.
*
* For apps running in the background on "O" devices, location is computed only once every 10
* minutes and delivered batched every 30 minutes. This restriction applies even to apps
* targeting "N" or lower which are run on "O" devices.
*
* This sample show how to use a long-running service for location updates. When an activity is
* bound to this service, frequent location updates are permitted. When the activity is removed
* from the foreground, the service promotes itself to a foreground service, and location updates
* continue. When the activity comes back to the foreground, the foreground service stops, and the
* notification assocaited with that service is removed.
*/
public class LocationUpdatesService extends Service {
private static final String PACKAGE_NAME =
"com.google.android.gms.location.sample.locationupdatesforegroundservice";
private static final String TAG = LocationUpdatesService.class.getSimpleName();
/**
* The name of the channel for notifications.
*/
private static final String CHANNEL_ID = "channel_01";
static final String ACTION_BROADCAST = PACKAGE_NAME + ".broadcast";
static final String EXTRA_LOCATION = PACKAGE_NAME + ".location";
private static final String EXTRA_STARTED_FROM_NOTIFICATION = PACKAGE_NAME +
".started_from_notification";
private final IBinder mBinder = new LocalBinder();
/**
* The desired interval for location updates. Inexact. Updates may be more or less frequent.
*/
private static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000;
/**
* The fastest rate for active location updates. Updates will never be more frequent
* than this value.
*/
private static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS =
UPDATE_INTERVAL_IN_MILLISECONDS / 2;
/**
* The identifier for the notification displayed for the foreground service.
*/
private static final int NOTIFICATION_ID = 12345678;
/**
* Used to check whether the bound activity has really gone away and not unbound as part of an
* orientation change. We create a foreground service notification only if the former takes
* place.
*/
private boolean mChangingConfiguration = false;
private NotificationManager mNotificationManager;
/**
* Contains parameters used by {@link com.google.android.gms.location.FusedLocationProviderApi}.
*/
private LocationRequest mLocationRequest;
/**
* Provides access to the Fused Location Provider API.
*/
private FusedLocationProviderClient mFusedLocationClient;
/**
* Callback for changes in location.
*/
private LocationCallback mLocationCallback;
private Handler mServiceHandler;
/**
* The current location.
*/
private Location mLocation;
public LocationUpdatesService() {
}
@Override
public void onCreate() {
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
mLocationCallback = new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
super.onLocationResult(locationResult);
onNewLocation(locationResult.getLastLocation());
}
};
createLocationRequest();
getLastLocation();
HandlerThread handlerThread = new HandlerThread(TAG);
handlerThread.start();
mServiceHandler = new Handler(handlerThread.getLooper());
mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// Android O requires a Notification Channel.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
CharSequence name = getString(R.string.app_name);
// Create the channel for the notification
NotificationChannel mChannel =
new NotificationChannel(CHANNEL_ID, name, NotificationManager.IMPORTANCE_DEFAULT);
// Set the Notification Channel for the Notification Manager.
mNotificationManager.createNotificationChannel(mChannel);
}
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(TAG, "Service started");
boolean startedFromNotification = intent.getBooleanExtra(EXTRA_STARTED_FROM_NOTIFICATION,
false);
// We got here because the user decided to remove location updates from the notification.
if (startedFromNotification) {
removeLocationUpdates();
stopSelf();
}
// Tells the system to not try to recreate the service after it has been killed.
return START_NOT_STICKY;
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mChangingConfiguration = true;
}
@Override
public IBinder onBind(Intent intent) {
// Called when a client (MainActivity in case of this sample) comes to the foreground
// and binds with this service. The service should cease to be a foreground service
// when that happens.
Log.i(TAG, "in onBind()");
stopForeground(true);
mChangingConfiguration = false;
return mBinder;
}
@Override
public void onRebind(Intent intent) {
// Called when a client (MainActivity in case of this sample) returns to the foreground
// and binds once again with this service. The service should cease to be a foreground
// service when that happens.
Log.i(TAG, "in onRebind()");
stopForeground(true);
mChangingConfiguration = false;
super.onRebind(intent);
}
@Override
public boolean onUnbind(Intent intent) {
Log.i(TAG, "Last client unbound from service");
// Called when the last client (MainActivity in case of this sample) unbinds from this
// service. If this method is called due to a configuration change in MainActivity, we
// do nothing. Otherwise, we make this service a foreground service.
if (!mChangingConfiguration && Utils.requestingLocationUpdates(this)) {
Log.i(TAG, "Starting foreground service");
/*
// TODO(developer). If targeting O, use the following code.
if (Build.VERSION.SDK_INT == Build.VERSION_CODES.O) {
mNotificationManager.startServiceInForeground(new Intent(this,
LocationUpdatesService.class), NOTIFICATION_ID, getNotification());
} else {
startForeground(NOTIFICATION_ID, getNotification());
}
*/
startForeground(NOTIFICATION_ID, getNotification());
}
return true; // Ensures onRebind() is called when a client re-binds.
}
@Override
public void onDestroy() {
mServiceHandler.removeCallbacksAndMessages(null);
}
/**
* Makes a request for location updates. Note that in this sample we merely log the
* {@link SecurityException}.
*/
public void requestLocationUpdates() {
Log.i(TAG, "Requesting location updates");
Utils.setRequestingLocationUpdates(this, true);
startService(new Intent(getApplicationContext(), LocationUpdatesService.class));
try {
mFusedLocationClient.requestLocationUpdates(mLocationRequest,
mLocationCallback, Looper.myLooper());
} catch (SecurityException unlikely) {
Utils.setRequestingLocationUpdates(this, false);
Log.e(TAG, "Lost location permission. Could not request updates. " + unlikely);
}
}
/**
* Removes location updates. Note that in this sample we merely log the
* {@link SecurityException}.
*/
public void removeLocationUpdates() {
Log.i(TAG, "Removing location updates");
try {
mFusedLocationClient.removeLocationUpdates(mLocationCallback);
Utils.setRequestingLocationUpdates(this, false);
stopSelf();
} catch (SecurityException unlikely) {
Utils.setRequestingLocationUpdates(this, true);
Log.e(TAG, "Lost location permission. Could not remove updates. " + unlikely);
}
}
/**
* Returns the {@link NotificationCompat} used as part of the foreground service.
*/
private Notification getNotification() {
Intent intent = new Intent(this, LocationUpdatesService.class);
CharSequence text = Utils.getLocationText(mLocation);
// Extra to help us figure out if we arrived in onStartCommand via the notification or not.
intent.putExtra(EXTRA_STARTED_FROM_NOTIFICATION, true);
// The PendingIntent that leads to a call to onStartCommand() in this service.
PendingIntent servicePendingIntent = PendingIntent.getService(this, 0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
// The PendingIntent to launch activity.
PendingIntent activityPendingIntent = PendingIntent.getActivity(this, 0,
new Intent(this, MainActivity.class), 0);
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
.addAction(R.drawable.ic_launch, getString(R.string.launch_activity),
activityPendingIntent)
.addAction(R.drawable.ic_cancel, getString(R.string.remove_location_updates),
servicePendingIntent)
.setContentText(text)
.setContentTitle(Utils.getLocationTitle(this))
.setOngoing(true)
.setPriority(Notification.PRIORITY_HIGH)
.setSmallIcon(R.mipmap.ic_launcher)
.setTicker(text)
.setWhen(System.currentTimeMillis());
// Set the Channel ID for Android O.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
builder.setChannelId(CHANNEL_ID); // Channel ID
}
return builder.build();
}
private void getLastLocation() {
try {
mFusedLocationClient.getLastLocation()
.addOnCompleteListener(new OnCompleteListener<Location>() {
@Override
public void onComplete(@NonNull Task<Location> task) {
if (task.isSuccessful() && task.getResult() != null) {
mLocation = task.getResult();
} else {
Log.w(TAG, "Failed to get location.");
}
}
});
} catch (SecurityException unlikely) {
Log.e(TAG, "Lost location permission." + unlikely);
}
}
private void onNewLocation(Location location) {
Log.i(TAG, "New location: " + location);
mLocation = location;
// Notify anyone listening for broadcasts about the new location.
Intent intent = new Intent(ACTION_BROADCAST);
intent.putExtra(EXTRA_LOCATION, location);
LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
// Update notification content if running as a foreground service.
if (serviceIsRunningInForeground(this)) {
mNotificationManager.notify(NOTIFICATION_ID, getNotification());
}
}
/**
* Sets the location request parameters.
*/
private void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
/**
* Class used for the client Binder. Since this service runs in the same process as its
* clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
LocationUpdatesService getService() {
return LocationUpdatesService.this;
}
}
/**
* Returns true if this is a foreground service.
*
* @param context The {@link Context}.
*/
public boolean serviceIsRunningInForeground(Context context) {
ActivityManager manager = (ActivityManager) context.getSystemService(
Context.ACTIVITY_SERVICE);
for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(
Integer.MAX_VALUE)) {
if (getClass().getName().equals(service.service.getClassName())) {
if (service.foreground) {
return true;
}
}
}
return false;
}
}
您可以使用WorkManager进行定期工作。 WorkManager将继续工作，不会有任何问题。服务可能会被终止。
答案 1 :(得分：0)
我将看一下Google的LocationUpdatesForegroundService示例项目：
https://github.com/googlesamples/android-play-location/tree/master/LocationUpdatesForegroundService
@ Al-Amin发布的解决方案似乎来自同一地点。尽管发布没有归属的其他人编写的代码根本不是很酷。