Android - Using Async to update UI

Question

I am puzzled with how to use Async. I am wanting it to update the UI as soon as a button is clicked without having to kill the activity and re instantiate it. In the background, I want it to be waiting for the click to update the UI, and after the click I want it to determine whether or not the correct button was clicked. I am using the boolean isUserRight(); to determine whether or not the answer is correct, and after that I am using resetButtons(); to reset the buttons (obviously) and then setButtons(); to change the button. I have the methods all written out, I just don't know how to implement them into Async. I need the UI to be updated instantly to change the color of a button. I don't need help with any of the methods, button color, etc, just the Async, and I'm not asking anybody to spoonfeed me either, just give me a little push on where to go. Any help would be nice, thanks guys!

TL;DR need to update UI after button is pushed using async so the button color doesn't get stuck and I don't have to restart the activity to update the UI. I don't need the whole code, just a little guidance on where to go.

Edit: Added some code.

This is on my onCreate();

buttons[0] = (Button)findViewById(R.id.b0);
    buttons[1] = (Button)findViewById(R.id.b1);
    buttons[2] = (Button)findViewById(R.id.b2);
    buttons[3] = (Button)findViewById(R.id.b3);
    buttons[0].setOnClickListener(this);
    buttons[1].setOnClickListener(this);
    buttons[2].setOnClickListener(this);
    buttons[3].setOnClickListener(this);

then under my onClick, I have a switch for the buttons which all go to this method:

    public boolean isUserRight() {
        if(correct == 1) {
              onButton();
            return true;
            //Toast.makeText(getApplicationContext(), "Good job!", Toast.LENGTH_SHORT).show();
            //buttons[test].getBackground().setColorFilter(Color.GREEN, PorterDuff.Mode.MULTIPLY);
        }
        onButton();
        return false;
    }


    public void onButton() {
        int rnd = new Random().nextInt(buttons.length);
        test = rnd;
        buttons[rnd].getBackground().setColorFilter(Color.YELLOW, PorterDuff.Mode.MULTIPLY);
        //ResetButtons();
    }

And this works fine, the only problem is after the first button being clicked, the colors stop changing and getting updated.

Answer 1

void test(){
    final Handler mHandler = new Handler(){

        @Override
        public void handleMessage(Message msg) {
            // TODO Auto-generated method stub
            super.handleMessage(msg);
            if(msg.what == 0){
                // update your ui

            }

        }

    };

    new Thread(new Runnable() {
        public void run() {
            // do network job
            // do something you want here
            mHandler.sendEmptyMessage(0);
        }
    }).start();

}

Answer 2

Alright, I fixed it. Thanks for all your help, to anybody who was wondering how I fixed it, I was using view.invalidate, which wasn't directed to anything so I had to change it to the buttons array ex.:

buttons[1].invalidate(); and that would refresh the buttons instead of the entire activity.