在特定屏幕上的应用程序中，即使屏幕被锁定，我也会向服务器发送位置更新。
以下是用于跟踪位置更新的GPSTracker服务类。
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
public static CommonInterfaces.UpdateLocationDelegate delegate;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
private static final int MY_PERMISSION_ACCESS_COURSE_LOCATION = 0;
// The minimum distance to change Updates in meters
public static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 20 meters
public static final long MAX_DISTANCE_CHANGE_FOR_UPDATES = 45; // considering 100 miles/hr
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000; // location update is based on distance, thus the value here is 0 ;//1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(){
mContext = null;
}
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
if (ActivityCompat.checkSelfPermission(mContext, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions((Activity)mContext, new String[]{
android.Manifest.permission.ACCESS_FINE_LOCATION
}, 10);
}
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// Getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// Getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// No network provider is enabled
} else {
this.canGetLocation = true;
// If GPS enabled, get latitude/longitude using GPS Services
if (isGPSEnabled) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
// Toast.makeText(getApplicationContext(), "GPS Location", Toast.LENGTH_SHORT).show();
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
if (isNetworkEnabled && (location == null)) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
// Toast.makeText(getApplicationContext(), "Network Location", Toast.LENGTH_SHORT).show();
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app.
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/Wi-Fi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog.
* On pressing the Settings button it will launch Settings Options.
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing the Settings button.
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// On pressing the cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
if (delegate != null) {
delegate.onUpdateLocation(location);
}
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
onLocationChanged方法检测位置更改并调用委托方法。但是，当设备锁定超过5分钟时，此服务不会更新位置。我猜测android正在进入睡眠模式，并在后台杀死应用程序。无论如何我可以在设备锁定时发送位置更新并避免进入睡眠模式吗？
答案 0 :(得分：2)
我在这个领域做了很多工作（在“永远”获得频繁的位置更新）。如果您每小时需要多次位置更新，唯一的方法是让您的服务位于Foreground（使用START_STICKY - 请参阅此示例）。如果服务保持在前台（即使在Doze Mode中），该服务几乎可以“永久”存在。在打盹模式下，位置更新可能会停止，因为某些传感器会“休眠”，但在打盹模式下服务不得受到影响。
您可以参考下一个Google示例：Location Updates in Foreground Sample
注意：请记住，前景服务也可以被Android杀死，如果它也需要（低内存等），但前景将是Android关闭的最后一件事。