android getRunningAppProcesses always returning null

Question

I have :-

Class Abc extends Activity(){

 private ActivityManager am;
 private List<RunningAppProcessInfo> rList;

     @Override
     public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);       
       setContentView(R.layout.main);
      }

     @Override
     public void onStart (Bundle savedInstanceState) {
       super.onStart(savedInstanceState);        
     }

     @Override
     public boolean onTouchEvent(MotionEvent event) {

        super.onTouchEvent(event);

        rList= am.getRunningAppProcesses();
        Log.e("MAIN", rList.isEmpty() +" .");

        return true;
     }
}

am.getRunningAppProcesses() is always null even though i have foreground apps running, the active applications also shows them correctly. i know that its supposed to return null if there's nothing else running, but i launch other apps (gmail, camera, for testing)

Is this a permissions issue?

Answer 1

figured it out.
For ActivityManager am , since the constructor is private , and no static instances are available, it must be instantiated like:

am = (ActivityManager)getSystemService(ACTIVITY_SERVICE);

Hope this is useful to someone stuck with a similar problem