如图所示，左边是五个fragment，点击可以正常切换。

我在书香建行这里加了一个读书fragment，和听书fragment相互切换，但是在看书界面点击左边按钮的时候会没反应，只有切换到听书才可以，这个要怎么加判断呢？以下是切换时的代码：

private void initFragment(int index) {
    // 由于是引用了V4包下的Fragment，所以这里的管理器要用getSupportFragmentManager获取
    FragmentManager fragmentManager = getSupportFragmentManager();
    // 开启事务
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    // 隐藏所有Fragment
    hideFragment(transaction);
    switch (index) {
        case R.id.iv_adver://金智惠民
            if (adverFragment == null) {
                adverFragment = new AdverFragment();
                transaction.add(R.id.content, adverFragment);
            } else {
                transaction.show(adverFragment);
            }
            break;
        case R.id.iv_news://时政新闻
            if (newsFragment == null) {
                newsFragment = new NewsFragment();
                transaction.add(R.id.content, newsFragment);
            } else {
                transaction.show(newsFragment);
            }

            break;
        case R.id.iv_photo://拍照
            if (photoFragment == null) {
                photoFragment = new ArPhotoFragment();
                transaction.add(R.id.content, photoFragment);
            } else {
                transaction.show(photoFragment);
            }

            break;
        case R.id.iv_weather://便民查询
            if (weatherFragment == null) {
                weatherFragment = new WeatherFragment();
                transaction.add(R.id.content, weatherFragment);
            } else {
                transaction.show(weatherFragment);
            }

            break;
        case R.id.iv_write://书香建行
            if (ximalayaFragment == null) {
                ximalayaFragment = new XimalayaFragment();
                transaction.add(R.id.content, ximalayaFragment);
            } else {
                transaction.show(ximalayaFragment);
            }
           /* if (writeFragment == null) {
                //writeFragment = new XinWriteFragment();
                writeFragment = new WriteFragment();
                transaction.add(R.id.content, writeFragment);
            } else {
                transaction.show(writeFragment);
                writeFragment.freeMpager();
                writeFragment.initBookShelf();
            }*/
            break;
        default:
            break;
    }
    // 提交事务
    transaction.commit();

}

private void hideFragment(FragmentTransaction transaction) {
    if (adverFragment != null) {
        transaction.hide(adverFragment);
    }
    if (newsFragment != null) {
        transaction.hide(newsFragment);
    }
    if (photoFragment != null) {
        transaction.hide(photoFragment);
    }
    if (weatherFragment != null) {
        transaction.hide(weatherFragment);
    }
    if (ximalayaFragment != null){
        transaction.hide(ximalayaFragment);
    }
    if (writeFragment != null) {
        transaction.hide(writeFragment);
    }
    if (blankFragment != null) {
        transaction.hide(blankFragment);
    }

}