how to show markers all the time by AsyncTask or Handler in google map version 2

Question

The final thing I am doing is: I have the google map in my application with som buttons and extra stuffs. but I also have to show the updated location of a marker all the time inside my map (I will get the data from external device not gps sensor of android phone). So I thought using thread first but then changes to AsyncTask as you see in my code and tried to use addMarker method there but every time I run it map just stopps working. I want to just show one marker on map now but now successful! The GoogleMap map cannot be reachable via UI thread and inside AsyncTask why? anybody encountered this? what should i do to solve this... plz help ``` package com.example.mapsversion2; //All imports public class MainActivity extends Activity { static final LatLng exmpoint = new LatLng(59.331438,18.064957); public static GoogleMap map; Button button; Button waypointButton; Button destinationButton; Marker wayPoint; TextView positiontext; int countclick= 3; public static DataModel autoboxdata= n…

Accepted Answer

You are trying to add a marker to the map in the background thread, but you can't update UI in Android from thread other than UI thread. So, move your `map.addMarker` call to the `onPostExecute` method, which is called in UI thread after background operation is complete:

```
public class PositionUpdate1  extends AsyncTask<Void, Void, Location> {

@Override
    protected Location doInBackground(Void...arg0) {
        // get your location...
        return hereIam;
    }

@Override
    protected void onPostExecute(Location loc) {
        map.addMarker(new MarkerOptions().position(loc));
    }
}
```

If you want to update the marker continuously, the easiest way is to use a `Handler`:

```
public class MainActivity extends Activity {

final int MARKER_UPDATE_INTERVAL = 2000; /* milliseconds */
    Handler handler = new Handler();

GoogleMap map;
    Marker marker;
    Location location;

Runnable updateMarker = new Runnable() {
        @Override
        public void run() {
            marker.remove();
            marker = map.addMarker(new MarkerOptions().position(location));

handler.postDelayed(this, MARKER_UPDATE_INTERVAL);
        }
    };

@Override
    public void onCreate(Bundle savedInstanceState) {
        map = ...; // get map
        location = ...; // get location
        marker = map.addMarker(new MarkerOptions().position(location));

handler.postDelayed(updateMarker, MARKER_UPDATE_INTERVAL);
    }

@Override
    protected void onDestroy() {
        handler.removeCallbacks(updateMarker);

super.onDestroy();
    }
}
```

how to show markers all the time by AsyncTask or Handler in google map version 2

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