How to display Toast in Android?

I have a slider that can be pulled up and then it shows a map. I can move the slider up and down to hide or show the map. When the map is on front, I can handle touch events on that map. Everytime I touch, a AsyncTask is fired up, it downloads some data and makes a Toast that displays the data. Although I start the task on touch event no toast is displayed, not till I close the slider. When the slider is closed and the map is not displayed anymore the Toast appears.

Any ideas?

Well start the task

EDIT:

public boolean onTouchEvent(MotionEvent event, MapView mapView){ 
    if (event.getAction() == 1) {
        new TestTask(this).execute();
        return true;            
    }else{
        return false;
    }
 }

and in onPostExecute make a toast

Toast.makeText(app.getBaseContext(),(String)data.result, 
                Toast.LENGTH_SHORT).show();

In new TestTask(this), this is a reference to MapOverlay and not to MapActivity, so this was the problem.

In order to display Toast in your application, try this:

Toast.makeText(getActivity(), (String)data.result, 
   Toast.LENGTH_LONG).show();

Another example:

Toast.makeText(getActivity(), "This is my Toast message!",
   Toast.LENGTH_LONG).show();

We can define two constants for duration:

int LENGTH_LONG Show the view or text notification for a long period of time.

int LENGTH_SHORT Show the view or text notification for a short period of time.

Customizing your toast

LayoutInflater myInflater = LayoutInflater.from(this);
View view = myInflater.inflate(R.layout.your_custom_layout, null);
Toast mytoast = new Toast(this);
mytoast.setView(view);
mytoast.setDuration(Toast.LENGTH_LONG);
mytoast.show();