通过javascript激活li

Question

我想让我的li使用javascript是活跃的。但问题是，当只点击一次时，它不起作用。需要连续2次点击才能激活。有人能帮我一下吗?

    <li data-popover="true" rel="popover" data-placement="right"><a href="#" data-target=".premium-menu" class="nav-header collapsed" data-toggle="collapse"><i class="fa fa-fw fa-book"></i> Lectures<i class="fa fa-collapse"></i></a></li>
    <li><ul class="premium-menu nav nav-list collapse in">
    <?php
         $sql ="SELECT enroll_ref FROM std_enrolled WHERE stud_no = '$stud_no'";
           $result = mysqli_query($con, $sql);
           while($row = mysqli_fetch_array($result)){
            $enroll_ref = $row['enroll_ref'];
             }

              $sql3 ="SELECT DISTINCT subj_descr FROM subj_enrolled WHERE enroll_ref = '$enroll_ref'";
           $results = mysqli_query($con, $sql3);
           while($row = mysqli_fetch_array($results)){
            $subj_descr = $row['subj_descr'];
    ?>
        <li><a class="item" href="viewlecture.php?subjdescr=<?php echo $subj_descr;?>"><span class="fa fa-caret-right"></span><?php echo ucwords(strtolower($subj_descr)); ?></a></li>
     <?php
      }  
     ?>
</ul></li>  
<script type="text/javascript">
$(".item").click(function() {
      $(this).parent('li').addClass("active");   
});
</script>

Answer 1

• 如果链接列表在每个viewlecture.php中或
设置类服务器端

• Ajax页面

  $(".item").on("click",function(e) { 
     e.preventDefault(); // stop link from reloading the page
     $("#lectureContainer").load(this.href); // load the lecture into a div or so
     $(this).closest("ul").find("li").removeClass("active"); 
     $(this).parent('li').addClass("active"); 
  });
  

有关更多示例，请参见此处设置基于URL的活动链接