我做了所有事情，但再次给出了 0.0 的纬度和经度

Question

用于获取位置的类

public class TrackGPS extends Service implements LocationListener {

private final Context mContext;

boolean checkGPS = false;

boolean checkNetwork = false;
boolean canGetLocation = false;
Location loc;
double latitude;
double longitude;

private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;

private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
protected LocationManager locationManager;
public TrackGPS(Context mContext) {
    this.mContext = mContext;
    getLocation();
}
private Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);
        // getting GPS status
        checkGPS = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);
        // getting network status
        checkNetwork = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);
        if (!checkGPS && !checkNetwork) {
            Toast.makeText(mContext, "No Service Provider Available", Toast.LENGTH_SHORT).show();
        } else {
            this.canGetLocation = true;
            // First get location from Network Provider
            if (checkNetwork) {
                Toast.makeText(mContext, "Network", Toast.LENGTH_SHORT).show();
                try {
                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("Network", "Network");
                    if (locationManager != null) {
                        loc = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    }
                    if (loc != null) {
                        latitude = loc.getLatitude();
                        longitude = loc.getLongitude();
                    }
                }
                catch(SecurityException e){
                }
            }
        }
        // if GPS Enabled get lat/long using GPS Services
        if (checkGPS) {
            Toast.makeText(mContext,"GPS",Toast.LENGTH_SHORT).show();
            if (loc == null) {
                try {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        loc = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (loc != null) {
                            latitude = loc.getLatitude();
                            longitude = loc.getLongitude();
                        }
                    }
                } catch (SecurityException e) {
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return loc;
}
public double getLongitude() {
    if (loc != null) {
        longitude = loc.getLongitude();
    }
    return longitude;
}
public double getLatitude() {
    if (loc != null) {
        latitude = loc.getLatitude();
    }
    return latitude;
}
public boolean canGetLocation() {
    return this.canGetLocation;
}
public void showSettingsAlert() {
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

    alertDialog.setTitle("GPS Not Enabled");
    alertDialog.setMessage("Do you wants to turn On GPS");

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

    alertDialog.setNegativeButton("No", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    });

    alertDialog.show();
}

public void stopUsingGPS() {
    if (locationManager != null) {
        locationManager.removeUpdates(TrackGPS.this);
    }
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle  ) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
 }
}

---

主活动代码为

 private static final int REQUEST_CODE_PERMISSION = 1;
 String mPermission = Manifest.permission.ACCESS_FINE_LOCATION
private Button b_get;
private TrackGPS gps;
double longitude;
double latitude;
//----------------------------------------------------------------
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    b_get = (Button)findViewById(R.id.locationBtn);


    b_get.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            gps = new TrackGPS(MainActivity.this);

            if(gps.canGetLocation()){

                longitude = gps.getLongitude();
                latitude = gps .getLatitude();
                Toast.makeText(getApplicationContext(),"Longitude:"+Double.toString(longitude)+"nLatitude:"+Double.toString(latitude),Toast.LENGTH_SHORT).show();
            }
            else
            {
                gps.showSettingsAlert();
            }
        }
    });
    if(Build.VERSION.SDK_INT>= 23) {
        if (checkSelfPermission(mPermission) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{mPermission,
                    },
                    REQUEST_CODE_PERMISSION);
            return ;
        }
        else
        {

        }
    }


protected void onDestroy() { super.onDestroy()  gps.stopUsingGPS();
    }

Answer 1

在

清单文件中添加所需的权限

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> 
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> 
<uses-permission android:name="android.permission.INTERNET"/>