Android 如何在没有互联网的情况下获得准确的当前纬度和经度

我是android新手。我想开发一个应用程序，在这个应用程序中，我想只向用户显示当前的纬度和经度，即使互联网没有连接。像这样的应用程序

我已经尝试了下面的代码。如果连接互联网，纬度和经度会发生变化。但如果互联网没有连接，如果我改变位置，纬度和经度将保持不变。但另一个应用程序，即链接中的上述应用程序运行良好。。请帮帮我。如何做到这一点

这是我的主要活动

   public class MainActivity extends AppCompatActivity {
private Toolbar toolbar;
GPSTracker gps;
TextView lat1, long1;
Button exit, refresh;
private PendingIntent pendingIntent;
private static MainActivity mInst;
double newLat, newLong;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    toolbar = (Toolbar) findViewById(R.id.app_bar);
    toolbar.setTitle("GPSFinder");
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    lat1 = (TextView) findViewById(R.id.latitude);
    long1 = (TextView) findViewById(R.id.longitude);
    exit = (Button) findViewById(R.id.button);
    exit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            finish();
        }
    });
    refresh = (Button) findViewById(R.id.buttonRefresh);

    Intent alarmIntent = new Intent(MainActivity.this, AlarmReceiver.class);
    pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, alarmIntent, 0);
    startAlarm();


    refresh.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            gps = new GPSTracker(MainActivity.this);

            // check if GPS enable
            if(gps.canGetLocation()){

                double latitude = gps.getLatitude();
                double longitude = gps.getLongitude();
                lat1.setText(""+latitude);
                long1.setText(""+longitude);

            }else{
                gps.showSettingsAlert();
            }
        }
    });

    gps = new GPSTracker(MainActivity.this);

    // check if GPS enabled
    if(gps.canGetLocation()){

        double latitude = gps.getLatitude();
        double longitude = gps.getLongitude();
        lat1.setText(""+latitude);
        long1.setText(""+longitude);

    }else{

        gps.showSettingsAlert();
    }

}


public void startAlarm(){
    AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

    /* Repeating on every 20 minutes interval */
    manager.setRepeating(AlarmManager.RTC_WAKEUP, 0,
            10 * 60 * 20, pendingIntent);

}

@Override
protected void onResume() {

    super.onResume();
    // Other onResume() code here
    this.registerReceiver(mMessageReceiver, new IntentFilter("some_unique_name"));
}

@Override
protected void onPause() {
    super.onPause();
    this.unregisterReceiver(mMessageReceiver);
    // Other onPause() code here

}
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {

        // Extract data included in the Intent
        String message = intent.getStringExtra("lat");
        String msg2 = intent.getStringExtra("long");
      //  updateYourActivity(context);
        lat1.setText(""+message);
        long1.setText(""+msg2);
        Log.e("dfsfdsf", "" + message);
        Log.e("dsfdgdgdfgfd",""+msg2);
        //update the TextView
      //  Toast.makeText(context, "Alarm Settttttttt", Toast.LENGTH_SHORT).show();
    }
};


}

这是GPSTracker类

  public class GPSTracker extends Service implements LocationListener {

private final 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 = 0; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 5 minutes

// Declaring a Location Manager
protected LocationManager locationManager;

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;
            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) {
     //   if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    public void requestPermissions(@NonNull String[] permissions, int requestCode)
            // 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 Activity#requestPermissions for more details.
            return;
        }
        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;
}

 }  

和AlarmReceiver类

  public class AlarmReceiver extends BroadcastReceiver {
GPSTracker gps;
double newLat, newLong;
String aString;
String bString;

@Override
public void onReceive(Context context, Intent intent) {

    updateYourActivity(context);
}

private void updateYourActivity(Context context) {

    Intent intent = new Intent("some_unique_name");

    // put whatever data you want to send, if any
    // intent.putExtra("message", message);

    gps = new GPSTracker(context);

    // check if GPS enabled
    if(gps.canGetLocation()){

        newLat = gps.getLatitude();
        newLong = gps.getLongitude();

        aString = Double.toString(newLat);
        bString = Double.toString(newLong);
        // lat1.setText(""+latitude);
        //long1.setText(""+longitude);

    Log.e("new lat",""+aString);
        Log.e("new long",""+bString);
    }else{

        gps.showSettingsAlert();
    }

    intent.putExtra("lat", aString);
    intent.putExtra("long", bString);
    context.sendBroadcast(intent);

}

 }

我尝试使用alarm manager不断更新纬度和经度值

我提供链接的应用程序在应用程序运行时在设备的状态栏上显示位置图标，在我退出应用程序后它就消失了

---

请帮助我如何执行此操作。

在函数GetLocation中，您应该在代码开头重置Location属性，因为如果（Location==null）从GPS获取代码，则它不会进入

块

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();
                    }
                }
            }
        }

在功能
OnLocationChanged（Android.Locations.Location位置）
中，您应该会收到新的GPS位置

    @Override
public void onLocationChanged(Location location) {
double lon = location.Longitude;
double lat = location.Latitude;

}

我更新答案。使用
locationManager.requestLocationUpdates（
您开始接收GPS更改，然后
onLocationChanged（Location Location）
将被触发。您是否能够获取GPS位置？或者是否有其他问题？我正在获取GPS位置OK，因此如果我的回答（该位置不是空的，并且onLocationChanged事件）帮助您，请将其设置为accpet，谢谢。您是否阅读了前面的评论？如果您找到了其他解决方案，请为此问题创建您自己的答案并将其关闭，谢谢。