我使用下面给出的代码来获取位置：
public Location getLocation() {
try {
mLocationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);
// getting GPS status
boolean isGPSEnabled = mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
boolean isNetworkEnabled = mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
// First get location from Network Provider
if (isNetworkEnabled) {
mLocationManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (mLocationManager != null) {
location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
lat = location.getLatitude();
lng = location.getLongitude();
}
}
}
//get the location by gps
if (isGPSEnabled) {
if (location == null) {
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MIN_TIME_BW_UPDATES,MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (mLocationManager != null) {location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
lat = location.getLatitude();
lng = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
它工作正常，但我想首先获得GPS位置，如果它不可用，位置管理员应该查询网络提供商，我遇到了麻烦。
请推荐我这样做的好方法。
答案 0 :(得分：18)
你说你首先需要GPS位置，但你所做的是首先从网络提供商那里获得位置，然后从GPS获得位置。如果两者都可用，这将从网络和GPS获得位置。您可以做的是，将这些案例写在 if..else if 块中。与 -
if( !isGPSEnabled && !isNetworkEnabled) {
// Can't get location by any way
} else {
if(isGPSEnabled) {
// get location from GPS
} else if(isNetworkEnabled) {
// get location from Network Provider
}
}
因此，这将首先从GPS获取位置（如果可用），否则它将尝试从网络提供商处获取位置。
修改：
为了让它更好，我会发布一个片段。请考虑它位于 try-catch ：
boolean gps_enabled = false;
boolean network_enabled = false;
LocationManager lm = (LocationManager) mCtx
.getSystemService(Context.LOCATION_SERVICE);
gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
Location net_loc = null, gps_loc = null, finalLoc = null;
if (gps_enabled)
gps_loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (network_enabled)
net_loc = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (gps_loc != null && net_loc != null) {
//smaller the number more accurate result will
if (gps_loc.getAccuracy() > net_loc.getAccuracy())
finalLoc = net_loc;
else
finalLoc = gps_loc;
// I used this just to get an idea (if both avail, its upto you which you want to take as I've taken location with more accuracy)
} else {
if (gps_loc != null) {
finalLoc = gps_loc;
} else if (net_loc != null) {
finalLoc = net_loc;
}
}
现在，您检查finalLoc null，如果不是return。
您可以在函数中编写上述代码，该函数返回所需的（finalLoc）位置。我认为这可能有所帮助。
答案 1 :(得分：5)
建议的方法是使用LocationClient：
首先，定义位置更新间隔值。根据您的需要进行调整。
private static final int MILLISECONDS_PER_SECOND = 1000;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;
让您Activity实施GooglePlayServicesClient.ConnectionCallbacks，GooglePlayServicesClient.OnConnectionFailedListener和LocationListener。
public class LocationActivity extends Activity implements
GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {}
然后，在LocationClient的{{1}}方法中设置onCreate()：
Activity将所需方法添加到public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mLocationClient = new LocationClient(this, this, this);
mLocationRequest = LocationRequest.create();
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationRequest.setInterval(UPDATE_INTERVAL);
mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
}
; Activity是onConnected()连接时调用的方法。 LocationClient是您可以检索最新位置的地方。
onLocationChanged()请确保连接/断开@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.w(TAG, "Location client connection failed");
}
@Override
public void onConnected(Bundle dataBundle) {
Log.d(TAG, "Location client connected");
mLocationClient.requestLocationUpdates(mLocationRequest, this);
}
@Override
public void onDisconnected() {
Log.d(TAG, "Location client disconnected");
}
@Override
public void onLocationChanged(Location location) {
if (location != null) {
Log.d(TAG, "Updated Location: " + Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude()));
} else {
Log.d(TAG, "Updated location NULL");
}
}
，以便在绝对必要时仅使用额外的电池，因此GPS无法无限期运行。必须连接LocationClient才能从中获取数据。
LocationClient获取用户的位置。首先尝试使用public void onResume() {
super.onResume();
mLocationClient.connect();
}
public void onStop() {
if (mLocationClient.isConnected()) {
mLocationClient.removeLocationUpdates(this);
}
mLocationClient.disconnect();
super.onStop();
}
;如果失败，请回到LocationClient。
LocationManager答案 2 :(得分：2)
使用谷歌开发人员开发的融合API，GPS传感器，磁力计，加速度计的融合也使用Wifi或小区位置来计算或估计位置。它还能够准确地在建筑物内提供位置更新。
package com.example.ashis.gpslocation;
import android.app.Activity;
import android.location.Location;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
/**
* Location sample.
*
* Demonstrates use of the Location API to retrieve the last known location for a device.
* This sample uses Google Play services (GoogleApiClient) but does not need to authenticate a user.
* See https://github.com/googlesamples/android-google-accounts/tree/master/QuickStart if you are
* also using APIs that need authentication.
*/
public class MainActivity extends Activity implements LocationListener,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener {
private static final long ONE_MIN = 500;
private static final long TWO_MIN = 500;
private static final long FIVE_MIN = 500;
private static final long POLLING_FREQ = 1000 * 20;
private static final long FASTEST_UPDATE_FREQ = 1000 * 5;
private static final float MIN_ACCURACY = 1.0f;
private static final float MIN_LAST_READ_ACCURACY = 1;
private LocationRequest mLocationRequest;
private Location mBestReading;
TextView tv;
private GoogleApiClient mGoogleApiClient;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (!servicesAvailable()) {
finish();
}
setContentView(R.layout.activity_main);
tv= (TextView) findViewById(R.id.tv1);
mLocationRequest = LocationRequest.create();
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationRequest.setInterval(POLLING_FREQ);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_FREQ);
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
if (mGoogleApiClient != null) {
mGoogleApiClient.connect();
}
}
@Override
protected void onResume() {
super.onResume();
if (mGoogleApiClient != null) {
mGoogleApiClient.connect();
}
}
@Override
protected void onPause() {d
super.onPause();
if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
tv.setText(location + "");
// Determine whether new location is better than current best
// estimate
if (null == mBestReading || location.getAccuracy() < mBestReading.getAccuracy()) {
mBestReading = location;
if (mBestReading.getAccuracy() < MIN_ACCURACY) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
}
@Override
public void onConnected(Bundle dataBundle) {
// Get first reading. Get additional location updates if necessary
if (servicesAvailable()) {
// Get best last location measurement meeting criteria
mBestReading = bestLastKnownLocation(MIN_LAST_READ_ACCURACY, FIVE_MIN);
if (null == mBestReading
|| mBestReading.getAccuracy() > MIN_LAST_READ_ACCURACY
|| mBestReading.getTime() < System.currentTimeMillis() - TWO_MIN) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
//Schedule a runnable to unregister location listeners
@Override
public void run() {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, MainActivity.this);
}
}, ONE_MIN, TimeUnit.MILLISECONDS);
}
}
}
@Override
public void onConnectionSuspended(int i) {
}
private Location bestLastKnownLocation(float minAccuracy, long minTime) {
Location bestResult = null;
float bestAccuracy = Float.MAX_VALUE;
long bestTime = Long.MIN_VALUE;
// Get the best most recent location currently available
Location mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
//tv.setText(mCurrentLocation+"");
if (mCurrentLocation != null) {
float accuracy = mCurrentLocation.getAccuracy();
long time = mCurrentLocation.getTime();
if (accuracy < bestAccuracy) {
bestResult = mCurrentLocation;
bestAccuracy = accuracy;
bestTime = time;
}
}
// Return best reading or null
if (bestAccuracy > minAccuracy || bestTime < minTime) {
return null;
}
else {
return bestResult;
}
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
private boolean servicesAvailable() {
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (ConnectionResult.SUCCESS == resultCode) {
return true;
}
else {
GooglePlayServicesUtil.getErrorDialog(resultCode, this, 0).show();
return false;
}
}
}
答案 3 :(得分：2)
如果您想在后台服务中运行并使用前面的数据，请使用下面的数据进行测试和验证。
public class MyService extends Service
implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
com.google.android.gms.location.LocationListener {
private static final int ASHIS = 1234;
Intent intentForPendingIntent;
HandlerThread handlerThread;
Looper looper;
GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRrequest;
private static final int UPDATE_INTERVAL = 1000;
private static final int FASTEST_INTERVAL = 100;
private static final int DSIPLACEMENT_UPDATES = 1;
;
private Handler handler1;
private Runnable runable1;
private Location mLastLocation;
private float waitingTime;
private int waiting2min;
private Location locationOld;
private double distance;
private float totalWaiting;
private float speed;
private long timeGpsUpdate;
private long timeOld;
private NotificationManager mNotificationManager;
Notification notification;
PendingIntent resultPendingIntent;
NotificationCompat.Builder mBuilder;
// Sets an ID for the notification
int mNotificationId = 001;
private static final String TAG = "BroadcastService";
public static final String BROADCAST_ACTION = "speedExceeded";
private final Handler handler = new Handler();
Intent intentforBroadcast;
int counter = 0;
private Runnable sendUpdatesToUI;
@Nullable
@Override
public IBinder onBind(Intent intent) {
Toast.makeText(MyService.this, "binder", Toast.LENGTH_SHORT).show();
return null;
}
@Override
public void onCreate() {
showNotification();
intentforBroadcast = new Intent(BROADCAST_ACTION);
Toast.makeText(MyService.this, "created", Toast.LENGTH_SHORT).show();
if (mGoogleApiClient == null) {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
createLocationRequest();
mGoogleApiClient.connect();
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private void showNotification() {
mBuilder =
(NotificationCompat.Builder) new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_media_play)
.setContentTitle("Total Waiting Time")
.setContentText(totalWaiting+"");
Intent resultIntent = new Intent(this, trackingFusion.class);
// Because clicking the notification opens a new ("special") activity, there's
// no need to create an artificial back stack.
PendingIntent resultPendingIntent =
PendingIntent.getActivity(
this,
0,
resultIntent,
PendingIntent.FLAG_UPDATE_CURRENT
);
mBuilder.setContentIntent(resultPendingIntent);
NotificationManager mNotifyMgr =
(NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// Builds the notification and issues it.
mNotifyMgr.notify(mNotificationId, mBuilder.build());
startForeground(001, mBuilder.getNotification());
}
@Override
public void onLocationChanged(Location location) {
//handler.removeCallbacks(runable);
Toast.makeText(MyService.this, "speed" + speed, Toast.LENGTH_SHORT).show();
timeGpsUpdate = location.getTime();
float delta = (timeGpsUpdate - timeOld) / 1000;
if (location.getAccuracy() < 100) {
speed = location.getSpeed();
distance += mLastLocation.distanceTo(location);
Log.e("distance", "onLocationChanged: " + distance);
//mLastLocation = location;
//newLocation = mLastLocation;
Log.e("location:", location + "");
//speed = (long) (distance / delta);
locationOld = location;
mLastLocation = location;
diaplayViews();
}
diaplayViews();
/*if (map != null) {
map.addMarker(new MarkerOptions()
.position(new LatLng(location.getLatitude(), location.getLongitude()))
.title("Hello world"));
}*/
}
private void createLocationRequest() {
mLocationRrequest = new LocationRequest();
mLocationRrequest.setInterval(UPDATE_INTERVAL);
mLocationRrequest.setFastestInterval(FASTEST_INTERVAL);
mLocationRrequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationRrequest.setSmallestDisplacement(DSIPLACEMENT_UPDATES);
}
private void methodToCalculateWaitingTime() {
if (handler1 != null) {
handler1.removeCallbacks(runable1);
}
Log.e("Here", "here1");
handler1 = new Handler(Looper.getMainLooper());
runable1 = new Runnable() {
public void run() {
Log.e("Here", "here2:" + mLastLocation.getSpeed());
if (mLastLocation != null) {
diaplayViews();
if ((mLastLocation.getSpeed() == 0.0)) {
increaseTime();
} else {
if (waitingTime <= 120) {
waiting2min = 0;
}
}
handler1.postDelayed(this, 10000);
} else {
if (ActivityCompat.checkSelfPermission(MyService.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(MyService.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;
}
locationOld = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
mLastLocation = locationOld;
}
}
};
handler1.postDelayed(runable1, 10000);
}
private void diaplayViews() {
float price = (float) (14 + distance * 0.5);
//textDistance.setText(waitingTime);a
}
private void increaseTime() {
waiting2min = waiting2min + 10;
if (waiting2min >= 120)
{
if (waiting2min == 120) {
waitingTime = waitingTime + 2 * 60;
} else {
waitingTime = waitingTime + 10;
}
totalWaiting = waitingTime / 60;
showNotification();
Log.e("waiting Time", "increaseTime: " + totalWaiting);
}
}
@Override
public void onDestroy() {
Toast.makeText(MyService.this, "distroyed", Toast.LENGTH_SHORT).show();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
mGoogleApiClient.disconnect();
}
@Override
public void onConnected(Bundle bundle) {
Log.e("Connection_fusion", "connected");
startLocationUpdates();
}
@Override
public void onConnectionSuspended(int i) {
}
private void startLocationUpdates() {
Location location = plotTheInitialMarkerAndGetInitialGps();
if (location == null) {
plotTheInitialMarkerAndGetInitialGps();
} else {
mLastLocation = location;
methodToCalculateWaitingTime();
}
}
private Location plotTheInitialMarkerAndGetInitialGps() {
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 null;
}
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRrequest, this);
locationOld = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if ((locationOld != null)) {
mLastLocation = locationOld;
timeOld = locationOld.getTime();
} else {
startLocationUpdates();
}
return mLastLocation;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
onStart(intent, startId);
Toast.makeText(MyService.this, "start command", Toast.LENGTH_SHORT).show();
sendUpdatesToUI = new Runnable() {
public void run() {
DisplayLoggingInfo();
handler.postDelayed(this, 10000); // 5 seconds
}
};
handler.postDelayed(sendUpdatesToUI, 10000); // 1 second
Log.i("LocalService", "Received start id " + startId + ": " + intent);
return START_NOT_STICKY;
}
@Override
public void onStart(Intent intent, int startId) {
sendUpdatesToUI = new Runnable() {
public void run() {
Log.e("sent", "sent");
DisplayLoggingInfo();
handler.postDelayed(this, 5000); // 5 seconds
}
};
handler.postDelayed(sendUpdatesToUI, 1000); // 1 second
Log.i("LocalService", "Received start id " + startId + ": " + intent);
super.onStart(intent, startId);
}
private void DisplayLoggingInfo() {
Log.d(TAG, "entered DisplayLoggingInfo");
intentforBroadcast.putExtra("distance", distance);
LocalBroadcastManager.getInstance(this).sendBroadcast(intentforBroadcast);
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
@Override
public void onMapReady(GoogleMap googleMap) {
}
}
答案 4 :(得分：1)
我在上面的代码中进行了一些更改，以便通过GPS和网络寻找定位修复大约5秒，并从中获取最知名的位置。
public class LocationService implements LocationListener {
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
final static long MIN_TIME_INTERVAL = 60 * 1000L;
Location location;
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 10
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1; // 1 minute
protected LocationManager locationManager;
private CountDownTimer timer = new CountDownTimer(5 * 1000, 1000) {
public void onTick(long millisUntilFinished) {
}
public void onFinish() {
stopUsingGPS();
}
};
public LocationService() {
super(R.id.gps_service_id);
}
public void start() {
if (Utils.isNetworkAvailable(context)) {
try {
timer.start();
locationManager = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
this.canGetLocation = true;
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
Location tempLocation = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (tempLocation != null
&& isBetterLocation(tempLocation,
location))
location = tempLocation;
}
}
if (isGPSEnabled) {
locationManager.requestSingleUpdate(
LocationManager.GPS_PROVIDER, this, null);
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 tempLocation = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (tempLocation != null
&& isBetterLocation(tempLocation,
location))
location = tempLocation;
}
}
} catch (Exception e) {
onTaskError(e.getMessage());
e.printStackTrace();
}
} else {
onOfflineResponse(requestData);
}
}
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(LocationService.this);
}
}
public boolean canGetLocation() {
locationManager = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
return isGPSEnabled || isNetworkEnabled;
}
@Override
public void onLocationChanged(Location location) {
if (location != null
&& isBetterLocation(location, this.location)) {
this.location = 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 Object getResponseObject(Object location) {
return location;
}
public static 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 > MIN_TIME_INTERVAL;
boolean isSignificantlyOlder = timeDelta < -MIN_TIME_INTERVAL;
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;
}
}
在上面的课程中，我正在为GPS和网络注册一个位置监听器，因此onLocationChanged回调可以被其中一个或两个调用多次，我们只是将新的位置定位与我们已经拥有并保持最好的一个。
答案 5 :(得分：1)
主类：
public class AndroidLocationActivity extends Activity {
Button btnGPSShowLocation;
Button btnNWShowLocation;
AppLocationService appLocationService;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
appLocationService = new AppLocationService(
AndroidLocationActivity.this);
btnGPSShowLocation = (Button) findViewById(R.id.btnGPSShowLocation);
btnGPSShowLocation.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Location gpsLocation = appLocationService
.getLocation(LocationManager.GPS_PROVIDER);
if (gpsLocation != null) {
double latitude = gpsLocation.getLatitude();
double longitude = gpsLocation.getLongitude();
Toast.makeText(
getApplicationContext(),
"Mobile Location (GPS): \nLatitude: " + latitude
+ "\nLongitude: " + longitude,
Toast.LENGTH_LONG).show();
} else {
showSettingsAlert("GPS");
}
}
});
btnNWShowLocation = (Button) findViewById(R.id.btnNWShowLocation);
btnNWShowLocation.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Location nwLocation = appLocationService
.getLocation(LocationManager.NETWORK_PROVIDER);
if (nwLocation != null) {
double latitude = nwLocation.getLatitude();
double longitude = nwLocation.getLongitude();
Toast.makeText(
getApplicationContext(),
"Mobile Location (NW): \nLatitude: " + latitude
+ "\nLongitude: " + longitude,
Toast.LENGTH_LONG).show();
} else {
showSettingsAlert("NETWORK");
}
}
});
}
public void showSettingsAlert(String provider) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(
AndroidLocationActivity.this);
alertDialog.setTitle(provider + " SETTINGS");
alertDialog.setMessage(provider
+ " is not enabled! Want to go to settings menu?");
alertDialog.setPositiveButton("Settings",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(
Settings.ACTION_LOCATION_SOURCE_SETTINGS);
AndroidLocationActivity.this.startActivity(intent);
}
});
alertDialog.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
下一课：
public class AppLocationService extends Service implements LocationListener {
protected LocationManager locationManager;
Location location;
private static final long MIN_DISTANCE_FOR_UPDATE = 10;
private static final long MIN_TIME_FOR_UPDATE = 1000 * 60 * 2;
public AppLocationService(Context context) {
locationManager = (LocationManager) context
.getSystemService(LOCATION_SERVICE);
}
public Location getLocation(String provider) {
if (locationManager.isProviderEnabled(provider)) {
locationManager.requestLocationUpdates(provider,
MIN_TIME_FOR_UPDATE, MIN_DISTANCE_FOR_UPDATE, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(provider);
return location;
}
}
return null;
}
@Override
public void onLocationChanged(Location 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;
}
}
不要忘记添加你的清单。
<!-- to get location using GPS -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- to get location using NetworkProvider -->
<uses-permission android:name="android.permission.INTERNET" />
答案 6 :(得分：-3)
有更好的方法来实现它在android开发者网站上提到的 http://developer.android.com/guide/topics/location/strategies.html