นี่คือสิ่งที่ฉันทำ:
- ก่อนอื่นฉันตรวจสอบว่ามีการเปิดใช้งาน NETWORK หรือ GPS หรือไม่ บางส่วนอาจถูกปิดการใช้งานบนอุปกรณ์บางอย่างอาจถูกปิดใช้งานในรายการแอปพลิเคชัน หากเปิดใช้งานผู้ให้บริการรายใดฉันจะดึงข้อมูลตำแหน่งสุดท้ายของแคชสำหรับผู้ให้บริการรายนี้และเริ่มอัปเดตตำแหน่งผู้ฟังสำหรับผู้ให้บริการนี้
- มีวิธีการตรวจสอบว่าสถานที่ตั้งนั้นดีกว่าสถานที่ที่ได้รับครั้งล่าสุดตามที่ระบุไว้ในลิงค์: - https://developer.android.com/guide/topics/location/strategies.html#BestEstimate
- หากฉันได้รับการอัปเดตจากผู้ฟังตำแหน่งฉันจะตรวจสอบว่าตำแหน่งนี้ดีกว่าตำแหน่งที่ได้รับก่อนหน้านี้หรือไม่ และหากดีกว่าแทนที่ตำแหน่งนี้เป็นตำแหน่งที่ดีที่สุดก่อนหน้า (
mFinalLocation )
- นอกจากนี้ยังมีตัวจัดการ (ตัวจับเวลา) เป็นเวลาสองนาทีซึ่งในที่สุดก็หยุดบริการและใน
onDestroy()วิธีการบริการหยุดฟังการอัพเดทตำแหน่งสำหรับผู้ให้บริการแต่ละราย
ด้านล่างเป็นรหัสสำหรับบริการ คุณสามารถเรียกใช้ได้ตามความถี่ของการอัปเดตตำแหน่งที่คุณต้องการ
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.support.annotation.Nullable;
import android.util.Log;
public class RecordLocationService extends Service {
private final String TAG = RecordLocationService.class.getSimpleName();
private final int TWO_MINUTES = 1000 * 60 * 2;
private LocationManager mLocationManager;
private MyLocationListener mLocationListeners[] = new MyLocationListener[]{
new MyLocationListener(LocationManager.NETWORK_PROVIDER),
new MyLocationListener(LocationManager.GPS_PROVIDER)
};
private Location mFinalLocation;
private class MyLocationListener implements LocationListener {
private String mProvider;
public MyLocationListener(String provider) {
Log.d(TAG, "LocationListener : " + provider);
mProvider = provider;
}
public String getProvider() {
return mProvider;
}
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "onLocationChanged : " + location);
if (isBetterLocation(location, mFinalLocation)) {
Log.d(TAG, "Setting current Final Location to recent most Location for Provider : " + location.getProvider());
Log.d(TAG, "Setting current Final Location to : " + location);
mFinalLocation = location;
} else {
Log.d(TAG, "Keeping current Final Location to previous Final Location");
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.d(TAG, "onStatusChanged provider " + provider);
}
@Override
public void onProviderEnabled(String provider) {
Log.d(TAG, "onProviderEnabled provider " + provider);
}
@Override
public void onProviderDisabled(String provider) {
Log.d(TAG, "onProviderDisabled provider " + provider);
}
}
private Handler mStopServiceHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 1: {
stopSelf();
}
break;
}
}
};
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
Log.d(TAG, "onStartCommand");
return START_STICKY;
}
@Override
public void onCreate() {
super.onCreate();
Log.d(TAG, "onCreate");
requestLocation();
mStopServiceHandler.sendEmptyMessageDelayed(1, TWO_MINUTES);
}
private void requestLocation() {
// Acquire a reference to the system Location Manager
if (mLocationManager == null) {
mLocationManager = (LocationManager) this.getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
}
try {
if (mLocationManager.getAllProviders().contains(LocationManager.NETWORK_PROVIDER) && mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
Log.d(TAG, "Fetching Cached Location for Provider : " + LocationManager.NETWORK_PROVIDER);
Location cachedNetworkLocation = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (cachedNetworkLocation != null) {
Log.d(TAG, "Setting Final Location to Cached Location for Provider : " + LocationManager.NETWORK_PROVIDER);
Log.d(TAG, "Setting Final Location to : " + cachedNetworkLocation);
mFinalLocation = cachedNetworkLocation;
} else {
Log.d(TAG, "Cached Location for Provider : " + LocationManager.NETWORK_PROVIDER + " is NULL");
}
Log.d(TAG, "Requesting Location Update for Provider : " + LocationManager.NETWORK_PROVIDER);
mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, mLocationListeners[0]);
}
} catch (SecurityException se) {
Log.e(TAG, se.getMessage(), se);
} catch (IllegalArgumentException iae) {
Log.e(TAG, iae.getMessage(), iae);
}
try {
if (mLocationManager.getAllProviders().contains(LocationManager.GPS_PROVIDER) && mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
Log.d(TAG, "Fetching Cached Location for Provider : " + LocationManager.GPS_PROVIDER);
Location cachedGPSLocation = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (cachedGPSLocation != null) {
if (isBetterLocation(cachedGPSLocation, mFinalLocation)) {
Log.d(TAG, "Setting Final Location to Cached Location for Provider : " + LocationManager.GPS_PROVIDER);
Log.d(TAG, "Setting Final Location to : " + cachedGPSLocation);
mFinalLocation = cachedGPSLocation;
}
} else {
Log.d(TAG, "Cached Location for Provider : " + LocationManager.GPS_PROVIDER + " is NULL");
}
Log.d(TAG, "Requesting Location Update for Provider : " + LocationManager.GPS_PROVIDER);
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mLocationListeners[1]);
}
} catch (SecurityException se) {
Log.e(TAG, se.getMessage(), se);
} catch (IllegalArgumentException iae) {
Log.e(TAG, iae.getMessage(), iae);
}
}
/**
* Determines whether one Location reading is better than the current Location fix
*
* @param location The new Location that you want to evaluate
* @param currentBestLocation The current Location fix, to which you want to compare the new one
*/
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() {
super.onDestroy();
Log.d(TAG, "onDestroy");
if (mLocationManager != null) {
for (int i = 0; i < mLocationListeners.length; i++) {
try {
Log.d(TAG, "Removing Location Update for Provider : " + mLocationListeners[i].getProvider());
mLocationManager.removeUpdates(mLocationListeners[i]);
} catch (Exception ex) {
Log.e(TAG, "fail to remove location listeners, ignore", ex);
}
}
}
}
}
