Question

我在android上开发了一个应用程序来检索用户的位置。事实上，我需要使用最可靠的服务，因为我需要一个非常精确的位置。

我现在不知道该怎么做，特别是因为我是初学者。

感谢您帮助我

Answer 1

您需要使用LocationManager来获取用户的经度和纬度。并GeoCoder获取位置名称和其他信息。（称为反向地理编码）请参阅以下文档。

http://developer.android.com/reference/android/location/Geocoder.html

http://developer.android.com/reference/android/location/LocationManager.html

以下代码会对您有所帮助。但我建议您浏览以上链接以获得正确的理解。

import java.util.List;
import java.util.Locale;

import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;

public class GeoSample extends Activity
{

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.viewmenu);

        LocationManager locationManager;
        String context = Context.LOCATION_SERVICE;
        locationManager = (LocationManager) getSystemService(context);

        Criteria crta = new Criteria();
        crta.setAccuracy(Criteria.ACCURACY_FINE);
        crta.setAltitudeRequired(false);
        crta.setBearingRequired(false);
        crta.setCostAllowed(true);
        crta.setPowerRequirement(Criteria.POWER_LOW);
        String provider = locationManager.getBestProvider(crta, true);

        // String provider = LocationManager.GPS_PROVIDER;
        Location location = locationManager.getLastKnownLocation(provider);
        updateWithNewLocation(location);

        locationManager.requestLocationUpdates(provider, 1000, 0,
                locationListener);
    }

    private final LocationListener locationListener = new LocationListener()
    {

        @Override
        public void onLocationChanged(Location location)
        {
            updateWithNewLocation(location);
        }

        @Override
        public void onProviderDisabled(String provider)
        {
            updateWithNewLocation(null);
        }

        @Override
        public void onProviderEnabled(String provider)
        {
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras)
        {
        }

    };

    private void updateWithNewLocation(Location location)
    {
        String latLong;
        TextView myLocation;
        myLocation = (TextView) findViewById(R.id.myLocation);

        String addressString = "no address found";

        if (location != null)
        {
            double lat = location.getLatitude();
            double lon = location.getLongitude();
            latLong = "Lat:" + lat + "\nLong:" + lon;

            double lattitude = location.getLatitude();
            double longitude = location.getLongitude();

            Geocoder gc = new Geocoder(this, Locale.getDefault());
            try
            {
                List<Address> addresses = gc.getFromLocation(lattitude,
                        longitude, 1);
                StringBuilder sb = new StringBuilder();
                if (addresses.size() > 0)
                {
                    Address address = (Address) addresses.get(0);
                    sb.append(address.getAddressLine(0)).append("\n");
                    sb.append(address.getLocality()).append("\n");
                    sb.append(address.getPostalCode()).append("\n");
                    sb.append(address.getCountryName());
                }
                addressString = sb.toString();
            } catch (Exception e)
            {
            }
        } else
        {
            latLong = " NO Location Found ";
        }
        myLocation.setText("your Current Position is :\n" + latLong + "\n "
                + addressString);
    }
}

请记住GPS提供商会为您提供准确的信息。但是需要一些时间并消耗更多电池。

希望这有帮助。

Answer 2

try {
            gps_enabled = locManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
        } catch (Exception ex) {
        }
        try {
            network_enabled = locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
        } catch (Exception ex) {
        }

        if (!gps_enabled && !network_enabled) {
             // show alert 
        }
        if (network_enabled) {
            locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListener);
        }
        if (gps_enabled) {
            locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locListener);
        }

如何有一个非常精确的地理位置？

2 个答案: