Actionbar Background Is Not Being Changed

I have tried with the following code to change the background of the actionbar. It works with 4.3 but not below 4.3. With the following code, null background is being set ie. old

Solution 1:

Finally,I found the solution. It was acheived by showing and hiding the title of action bar after setting background.

getActionBar().setBackgroundDrawable(ContextCompat.getDrawable(this,R.drawable.inbox_header)); 
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);

Thank you all for your concern.

Solution 2:

The only think that you can do is to call invalidateOptionsMenu () after setting background for actionbar..

publicvoidonStartClicked(View v){
        int Min = 0;
        int Max = 2;

        //Random number generator between 0 and 2 inclusiveint pos = Min + (int) (Math.random() * ((Max - Min) + 1));

        if (pos == 0) {
            getActionBar().setBackgroundDrawable(
                    getResources().getDrawable(R.drawable.header));
        } elseif (pos == 1) {
            getActionBar().setBackgroundDrawable(
                    getResources().getDrawable(R.drawable.inbox_header));

        } elseif (pos == 2) {
            getActionBar().setBackgroundDrawable(
                    getResources().getDrawable(R.drawable.outbox_header));

        }
       invalidateOptionsMenu();
    }