问题描述
我的工作围绕创建将在其自身的进程中运行后台服务。这应该让我听,如果设备的位置发生了变化。我应该能够改变标准像通知用户界面之前,移动的距离。
I am working around creating a background service that will run in its own process. It should allow me to listen if the device location has changed. I should be able to change criteria like the distance moved before notifying the UI.
我怎么能这样做?我服务的一个小的知识和 LocationListener的
的实施。周围的净任何教程将AP preciated。
How can I do the same? I have a little knowledge of service and LocationListener
implementations. Any tutorials around the net would be appreciated.
我得到了一个back-link从堆栈溢出,但我不明白太多。
I got one back-link from stack overflow, but I didn't understand much of it.
推荐答案
首先,你需要创建一个服务
。在该服务
,创建一个类扩展 LocationListener的
。为此,请使用以下code 服务
的片断:
First you need to create a Service
. In that Service
, create a class extending LocationListener
. For this, use the following code snippet of Service
:
public class LocationService extends Service
{
public static final String BROADCAST_ACTION = "Hello World";
private static final int TWO_MINUTES = 1000 * 60 * 2;
public LocationManager locationManager;
public MyLocationListener listener;
public Location previousBestLocation = null;
Intent intent;
int counter = 0;
@Override
public void onCreate()
{
super.onCreate();
intent = new Intent(BROADCAST_ACTION);
}
@Override
public void onStart(Intent intent, int startId)
{
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
listener = new MyLocationListener();
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 4000, 0, listener);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 4000, 0, listener);
}
@Override
public IBinder onBind(Intent intent)
{
return null;
}
protected boolean isBetterLocation(Location location, Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return true;
}
// Check whether the new location fix is newer or older
long timeDelta = location.getTime() - currentBestLocation.getTime();
boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
boolean isNewer = timeDelta > 0;
// If it's been more than two minutes since the current location, use the new location
// because the user has likely moved
if (isSignificantlyNewer) {
return true;
// If the new location is more than two minutes older, it must be worse
} else if (isSignificantlyOlder) {
return false;
}
// Check whether the new location fix is more or less accurate
int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy());
boolean isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 200;
// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(location.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and accuracy
if (isMoreAccurate) {
return true;
} else if (isNewer && !isLessAccurate) {
return true;
} else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
return true;
}
return false;
}
/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}
@Override
public void onDestroy() {
// handler.removeCallbacks(sendUpdatesToUI);
super.onDestroy();
Log.v("STOP_SERVICE", "DONE");
locationManager.removeUpdates(listener);
}
public static Thread performOnBackgroundThread(final Runnable runnable) {
final Thread t = new Thread() {
@Override
public void run() {
try {
runnable.run();
} finally {
}
}
};
t.start();
return t;
}
public class MyLocationListener implements LocationListener
{
public void onLocationChanged(final Location loc)
{
Log.i("**************************************", "Location changed");
if(isBetterLocation(loc, previousBestLocation)) {
loc.getLatitude();
loc.getLongitude();
intent.putExtra("Latitude", loc.getLatitude());
intent.putExtra("Longitude", loc.getLongitude());
intent.putExtra("Provider", loc.getProvider());
sendBroadcast(intent);
}
}
public void onProviderDisabled(String provider)
{
Toast.makeText( getApplicationContext(), "Gps Disabled", Toast.LENGTH_SHORT ).show();
}
public void onProviderEnabled(String provider)
{
Toast.makeText( getApplicationContext(), "Gps Enabled", Toast.LENGTH_SHORT).show();
}
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
}
}
将此服务
项目中的任何地方,你想要的方式! :)
Add this Service
any where in your project, the way you want! :)
这篇关于在Android的位置监听器后台服务的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!