​您好，我有一个归档帖子页面，在那里我动态地拉入帖子，然后按年份然后按月排序。我正在尝试添加引导手风琴效果，将一年中的几个月隐藏起来，直到单击为止。

我正在使用echo$year\\u current为每年生成一个唯一的id。但出于某种原因，它仍然不起作用。只是第一年，其他一切都隐藏了起来。我在它上面有一个计数器来应用\'。“在”类中

  <?php $c = 0; ?>
<div id="collapse-<?php echo $year_current; ?>" class="panel-collapse collapse <?php if( $c == 1 ) echo \'in\'; ?>" role="tabpanel" aria-labelledby="heading-<?php echo $year_current; ?>">

  <?php
/*
Template Name: Archives
*/
get_header(); ?>

<div id="mid_yellow">
  <p>Archives</p>
</div>
  <div id="mid_yellow">
  </div>
    <p ></p>
    <?php $c = 0; ?>
    <?php
    global $wpdb;

    $limit = 0;
    $year_prev = null;
    $months = $wpdb->get_results("SELECT DISTINCT MONTH( post_date ) AS month , YEAR( post_date ) AS year, COUNT( id ) as post_count FROM $wpdb->posts WHERE post_status = \'publish\' and post_date <= now( ) and post_type = \'post\' GROUP BY month , year ORDER BY post_date DESC");

    foreach($months as $month) :

        $year_current = $month->year; $c++;

        if ($year_current != $year_prev)
        {
            if($year_current != date(\'Y\'))
            {
            ?>
                </ul>
            <?php
            }
            ?>

<div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
  <div class="panel panel-default">
    <div class="panel-heading" role="tab" id="heading-<?php echo $year_current; ?>">
      <h4 class="panel-title">
            <a data-toggle="collapse" data-parent="#accordion" aria-controls="collapse-<?php echo $year_current; ?>" href="#collapse-<?php echo $year_current; ?>/"><?php echo $month->year; ?></a>
        </h4>
    </div>

    <div id="collapse-<?php echo $year_current; ?>" class="panel-collapse collapse <?php if( $c == 1 ) echo \'in\'; ?>" role="tabpanel" aria-labelledby="heading-<?php echo $year_current; ?>">
      <ul class=\'list-group\'>
        <?php
        }
        ?>

            <li class=\'list-group-item\'>
                <a href="<?php bloginfo(\'url\') ?>/<?php echo $month->year; ?>/<?php echo date("m", mktime(0, 0, 0, $month->month, 1, $month->year)) ?>"><span class="archive-month"><?php echo date_i18n("F", mktime(0, 0, 0, $month->month, 1, $month->year)) ?></span></a>
            </li>

        <?php
        $year_prev = $year_current;

    endforeach;
    ?>
      </ul>
    </div>
  </div>
</div>

<?php get_footer(); ?>