get latitude location after fixed interval

问题

For a speed measuring app, I need to get the latitude and longitude updates after every four seconds. I've used the sleep function between the two calls to getLatitude and getLongitude functions. But printing it on screen shows the value remains the same i.e. lon1 and lon2, as doubles (14 places after the decimal) have exactly the same value and hence speed too is shown 0.

How to get Latitude and Longitude after fixed intervals of time (4 secs here)? Much thanks in advance.

   locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

        locationListener = new LocationListener()
        {
            @Override
            public void onLocationChanged(Location location) {
                double r = 6371;
                double lat1 = location.getLatitude();
                double lon1 = location.getLongitude(); // To get initial longitude
                SystemClock.sleep(4000);              /////This seems ineffective.
                double lat2 = location.getLatitude();
                double lon2 = location.getLongitude(); // and here
                double dlat = (lat2-lat1)*22/7/180;
                double dlon = (lon2-lon1)*22/7/180;
             
                textView.append("lon1:"+lon1+" lon2:"+lon2+" Kmph\n");
                lat1 = lat1*22/7/180;
                lat2 = lat2*22/7/180;
                double h = ((1-Math.cos(dlat))/2) + Math.cos(lat1)*Math.cos(lat2)*(1-Math.cos(dlon))/2;
                double d = 2**Math.asin(Math.sqrt(h));
                double sp = d/3;
                textView.append(" "+ sp + " Kmph\n");
            }

            

            @Override
            public void onStatusChanged(String s, int i, Bundle bundle) {

            }

            @Override
            public void onProviderEnabled(String s) {

            }

            @Override
            public void onProviderDisabled(String s) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                startActivity(intent);
            }
        };
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{
                        Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.ACCESS_COARSE_LOCATION,
                        Manifest.permission.INTERNET
                },10);
                return;
            }
        }else {
            configureButton();
        }

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode) {
            case 10:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
                    configureButton();
                return;
        }
    }

    private void configureButton() {
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                locationManager.requestLocationUpdates("gps", 4000, 0, locationListener);
            }
        });

    }
}

回答1:

Hey i'm not sure but you are looking something like this Hope this will help you.

  float oldlat, oldlng;
  float currentLat, currentLng;


  // Use this in location changed 
  currentLat = (float) location.getLatitude();
  currentLng = (float) location.getLongitude();

   final Handler handler = new Handler();
   handler.postDelayed(new Runnable() {
   @Override
   public void run() {

        oldlat = (float) location.getLatitude();
        oldlng = (float) location.getLongitude();

   }
   }, 4000);

来源：https://stackoverflow.com/questions/40491336/get-latitude-location-after-fixed-interval