Actionbar - Cập nhật icon actionbar

private boolean isPlaying;
MenuItem mPlayMenuItem;
MenuItem mPauseMenuItem;

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu items for use in the action bar
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.actionbarlogic, menu);

    mPlayMenuItem = menu.findItem(R.id.action_play);
    mPauseMenuItem = menu.findItem(R.id.action_pause);

    return super.onCreateOptionsMenu(menu);

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    switch (item.getItemId()) {
        case R.id.action_play:
            isPlaying = true;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
                this.invalidateOptionsMenu();
            }
            return true;
        case R.id.action_pause:
            isPlaying = false;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
                this.invalidateOptionsMenu();
            }
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}


 @Override
public boolean onPrepareOptionsMenu (Menu menu) {
    super.onPrepareOptionsMenu(menu);

    if (isPlaying) {
        mPlayMenuItem.setVisible(false); // hide play button
        mPauseMenuItem.setVisible(true); // show the pause button
    } else if (!isPlaying) {
        mPlayMenuItem.setVisible(true); // show play button
        mPauseMenuItem.setVisible(false); // hide the pause button
    }

    return true;
}

Tham khảo : http://stackoverflow.com/questions/11006749/change-icons-in-actionbar-dynamically