Tabactivity 返回键失效

    /**
     * 退出
     */
    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK
                && event.getAction() == KeyEvent.ACTION_DOWN
                && event.getRepeatCount() == 0) {            
            //具体的操作代码
        }
        return super.dispatchKeyEvent(event);
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
    }