某些设备返回纬度和经度 0.0

Question

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;

public class GPSTracker extends Service implements LocationListener {

    private  Context mContext;

    // flag for GPS status
    boolean isGPSEnabled = false;

    // flag for network status
    boolean isNetworkEnabled = false;

    // flag for GPS status
    boolean canGetLocation = false;

    Location location; // location
    double latitude; // latitude
    double longitude; // longitude

    // The minimum distance to change Updates in meters
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;
    public GPSTracker( ) {

    }
    public GPSTracker(Context context) {
        this.mContext = context;
        getLocation();
    }

    public Location getLocation() {
        try {
            locationManager = (LocationManager) mContext
                    .getSystemService(LOCATION_SERVICE);

            // getting GPS status
            isGPSEnabled = locationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);

            // getting network status
            isNetworkEnabled = locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
                // no network provider is enabled
            } else {
                this.canGetLocation = true;
                // First get location from Network Provider
                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 = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
                // if GPS Enabled get lat/long using GPS Services
                if (isGPSEnabled) {
                    if (location == 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 = locationManager
                                    .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            if (location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return location;
    }

    /**
     * Stop using GPS listener
     * Calling this function will stop using GPS in your app
     * */
    public void stopUsingGPS(){
        if(locationManager != null){
            locationManager.removeUpdates(GPSTracker.this);
        }
    }

    /**
     * Function to get latitude
     * */
    public double getLatitude(){
        if(location != null){
            latitude = location.getLatitude();
        }

        // return latitude
        return latitude;
    }

    /**
     * Function to get longitude
     * */
    public double getLongitude(){
        if(location != null){
            longitude = location.getLongitude();
        }

        // return longitude
        return longitude;
    }

    /**
     * Function to check GPS/wifi enabled
     * @return boolean
     * */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }

    /**
     * Function to show settings alert dialog
     * On pressing Settings button will lauch Settings Options
     * */
    public void showSettingsAlert(){
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });

        // on pressing cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }

    @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;
    }

}

活动调用

  GPSTracker   gpsTracker=new GPSTracker(CitymanagerActivity.this);
   if (gpsTracker.canGetLocation()) {

                double latitude = gpsTracker.getLatitude();
                double longitude = gpsTracker.getLongitude();
                Toast.makeText(CitymanagerActivity.this, latitude + " @@@Works@@@ " + longitude + "", Toast.LENGTH_LONG).show();
            }

Answer 1

1) 不要使用 GPSTracker。众所周知，这个类已经被彻底破坏了多年。它有时会起作用，但在概念层面上它对位置的假设存在缺陷。我在这里有一篇关于它的博文：http://gabesechansoftware.com/location-tracking/

2)当您假设 getLastKnownLocation 有效时会发生这种情况。它很少是。它应该仅用作优化，然后仅在您知道自己在做什么的情况下使用。 GPSTracker 的作者没有。

Answer 2

有时返回lat long 需要时间。添加一个 if else 条件以检查 lat long 是否为 0.0。如果 lat long 为 0，则再次调用该方法以获取位置。我也遇到了同样的问题，所以我一次又一次地调用该方法，在两次三击之后，它给出了纬度。

注意： GPS Tracker 是非常古老的代码。除了使用它，您还可以使用 Fused api 进行定位。

我的代码：

private void getLatLong() {
        try {
            mLatitudeOrigin = GPSTracker.latitude;
            mLongitudeOrigin = GPSTracker.longitude;

            if (mLatitudeOrigin.toString().equals("0.0")) {
                new Handler().postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        mLatitudeOrigin = GPSTracker.latitude;
                        mLongitudeOrigin = GPSTracker.longitude;

                        if (mLatitudeOrigin.toString().equals("0.0")) {
                            getLatLong();
                        }
                        System.out.println("---mLatLngList iterateAllLocation 1---" + mLatLngList);

                    }
                }, 1000);
            } else {
                System.out.println("---mLatLngList iterateAllLocation 2---" + mLatLngList);

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }