问题
In my Android application, I want to use both the GPS provider and the network provider for location updates for 5 seconds. First, I would like to use GPS provider (because it gives accurate results), and if the GPS provider returns latitude and longitude as 0.0 and 0.0, then I want to use network provider, but I don't want to use both the providers simultaneously. Any suggestions?
回答1:
package loca.loca;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.Toast;
public class LocationActivity extends Activity {
double x,y;
Timer timer;
LocationManager lm;
boolean gps_enabled = false;
boolean network_enabled = false;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!gps_enabled && !network_enabled) { Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "nothing is enabled", duration);
toast.show();
}
if (gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
locationListenerGps);
if (network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0,
locationListenerNetwork);
timer=new Timer();
timer.schedule(new GetLastLocation(), 20000);
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer.cancel();
x =location.getLatitude();
y = location.getLongitude();
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "gps enabled "+x + "\n" + y, duration);
toast.show();
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer.cancel();
x = location.getLatitude();
y = location.getLongitude();
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "network enabled"+x + "\n" + y, duration);
toast.show();
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
class GetLastLocation extends TimerTask {
@Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
{x = gps_loc.getLatitude();
y = gps_loc.getLongitude();
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "gps lastknown "+x + "\n" + y, duration);
toast.show();
}
else
{x = net_loc.getLatitude();
y = net_loc.getLongitude();
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "network lastknown "+x + "\n" + y, duration);
toast.show();
}
}
if(gps_loc!=null){
{x = gps_loc.getLatitude();
y = gps_loc.getLongitude();
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "gps lastknown "+x + "\n" + y, duration);
toast.show();
}
}
if(net_loc!=null){
{x = net_loc.getLatitude();
y = net_loc.getLongitude();
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "network lastknown "+x + "\n" + y, duration);
toast.show();
}
}
Context context = getApplicationContext();
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, "no last know avilable", duration);
toast.show();
}
}}
回答2:
public class MyLocation {
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;`
public boolean getLocation(Context context, LocationResult result)
{
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
try{
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 30000);
}catch(Exception x){
return false;
}
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
@Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(gps_loc);
else
locationResult.gotLocation(net_loc);
return;
}
if(gps_loc!=null){
locationResult.gotLocation(gps_loc);
return;
}
if(net_loc!=null){
locationResult.gotLocation(net_loc);
return;
}
locationResult.gotLocation(null);
}
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
}
then use these in your activity:
final MyLocation myLocation = new MyLocation();
Handler mHandler = new Handler(Looper.getMainLooper());
mHandler.post(new Runnable() {
public void run() {
locationResult = new LocationResult(){
@Override
public void gotLocation(final Location location){
//Got the location!
try{
Methods.savePre(context, ""+location.getLatitude(), "LATITUDE");
Methods.savePre(context, ""+location.getLongitude(), "LONGITUDE");
}catch(Exception x){
x.getMessage();
}
Got_loc= true;
// String geoAddress = "geo:" + location.getLatitude() + ","+ location.getLongitude() + "?z=15";
// Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(geoAddress));
// context.startActivity(intent);
}
};
myLocation.getLocation(context, locationResult);
}
});
while(!Got_loc){
Thread.sleep(150);
}
Loc = Methods.getPref(context, "LATITUDE") + "%%" + Methods.getPref
回答3:
The simplest way is to create two different LocationListener and two request location for both gps and network.
来源：https://stackoverflow.com/questions/10122358/how-to-use-both-gps-and-network-provider-to-get-current-location-latitude-and-lo