我想每15分钟在后台获取当前位置。我已经用Timer创建了一个后台服务。但是它在某个时间点停止。
请纠正我，如何一直在后台不间断地运行此程序？
public class BackgroundService extends Service implements LocationListener {
public static String str_receiver = "app.BackgroundService.Locationreceiver";
boolean isGPSEnable = false;
boolean isNetworkEnable = false;
double latitude, longitude;
LocationManager locationManager;
Location location;
long notify_interval = 600000;
Intent intent;
private Handler mHandler = new Handler();
private Timer mTimer = null;
public BackgroundService() {
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
super.onCreate();
Toast.makeText(BackgroundService.this, "Getting Location", Toast.LENGTH_SHORT).show();
mTimer = new Timer();
mTimer.schedule(new TimerTaskToGetLocation(), 60000, notify_interval);
intent = new Intent(str_receiver);
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
private void fn_getlocation() {
locationManager = (LocationManager) getApplicationContext().getSystemService(LOCATION_SERVICE);
isGPSEnable = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnable = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnable && !isNetworkEnable) {
Toast.makeText(BackgroundService.this, "GPS disabled", Toast.LENGTH_LONG).show();
} else {
if (isNetworkEnable) {
location = null;
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;
}
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000000, 20, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
Log.e("latitude", location.getLatitude() + "");
Log.e("longitude >>", location.getLongitude() + "");
latitude = location.getLatitude();
longitude = location.getLongitude();
fn_update(location);
}
}
}
if (isGPSEnable) {
location = null;
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;
}
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000000, 20, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
Log.e("latitude>>", location.getLatitude() + "");
Log.e("longitude", location.getLongitude() + "");
latitude = location.getLatitude();
longitude = location.getLongitude();
fn_update(location);
}
}
}
}
}
private void fn_update(Location location) {
intent.putExtra("latutide", location.getLatitude() + "");
intent.putExtra("longitude", location.getLongitude() + "");
sendBroadcast(intent);
}
private class TimerTaskToGetLocation extends TimerTask {
@Override
public void run() {
mHandler.post(new Runnable() {
@Override
public void run() {
fn_getlocation();
}
});
}
}
在清单中
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
东西是位置服务对于Android是昂贵。因此，当应用进入后台时，android os会停止大量后台服务。这就是为什么您不获取位置的原因，或者在某些情况下，您可能会获得旧位置本身。
请对此进行查看，android中的背景执行限制对于问题有想法。
因此，您应该使用ForegroundService在服务运行时生成Notification。
它的onCreate（）有点像
override fun onCreate() {
super.onCreate()
log("The service has been created".toUpperCase())
var notification = createNotification()
startForeground(1, notification)
}
并且应该以...开头
context.startForegroundService(it)
这里是有关其详细实现的文章。我希望这会对您有帮助。