setBackgroundResource doesn't set the image

Question

    Handler hnd = new Handler() {

    @Override
    public void handleMessage(Message msg) {

        int id = sequence.get(msg.arg1);

        if(msg.arg1 % 2 == 0         


        

Answer 1

public void show(int size) {

    // CICLE THROUGH EACH SQUARE

    for(int i = 0; i <= size-1; i++) {          

        Thread thrd = new Thread() {
            public void run() {
                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                                           sq.get(id-1).setImageResource(R.drawable.square_show);         
                               //     System.out.println("1st.........."); 
                       try {
                        sleep(2000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                                         sq.get(id-1).setImageResource(R.drawable.square);
                  //     System.out.println("2nd..........");
                       try {
                        sleep(2000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    }
                });




            }
        };

        thrd.start();
    }
}