Question

我想在ul有一个孩子的地方添加css右箭头？下面是三角形右css。我想在我的菜单中添加，以便用户知道此菜单有子菜单。

如果li有孩子的ul.children，如何在纯css中检测？

我想在下面添加三角形右箭头到我的CSS。 Plz帮助。

菜单的php代码：

<?php
$stmt = $pdo->query('SELECT * FROM `category` where `parent_id` = 0');
$stmt->execute();
?>

<ul class="top-level-menu">
    <?php while($menu1 = $stmt->fetch()){ ?>
        <li><a href="<?php echo $menu1['category_link'] . "\n"; ?>"><?php echo $menu1['product'] . "\n"; ?></a>

            <?php   $stmt1 = $pdo->prepare('SELECT * FROM category WHERE parent_id = ?');
                    $stmt1->execute([$menu1['id']]);
                    ?>
                    <ul class="second-level-menu">
                        <?php while($menu2 = $stmt1->fetch()){ ?>
                        <li><a href="<?php echo $menu2['category_link'] . "\n"; ?>"><?php echo $menu2['product'] . "\n"; ?></a>
                                    <?php
                                    $stmt2 = $pdo->prepare('SELECT * FROM category WHERE parent_id = ?');
                                    $stmt2->execute([$menu2['id']]);
                                    ?>
                                <ul class="third-level-menu">
                                    <?php while($menu3 = $stmt2->fetch()){ ?>
                                   <li><a href="<?php echo $menu3['category_link'] . "\n"; ?>"><?php echo $menu3['product'] . "\n"; ?></a>
                                   </li>
                                   <?php } ?>
                                </ul>

                        </li>

                        <?php } ?>
                    </ul>


        </li>
<?php } ?>
</ul>

菜单栏的

css

<style>
/* Menu Styles */

.third-level-menu
{
    position: absolute;
    top: 0;
    right: -220px;
    width: 220px;
    list-style: none;
    padding: 0;
    margin: 0;
    display: none;
}

.third-level-menu > li
{
    height: 30px;
    background: #999999;
}
.third-level-menu > li:hover { background: #CCCCCC; }

.second-level-menu
{
    position: absolute;
    top: 30px;
    left: 0;
    width: 200px;
    list-style: none;
    padding: 0;
    margin: 0;
    display: none;
}

.second-level-menu > li
{
    position: relative;
    height: 30px;
    background: #999999;
}
.second-level-menu > li:hover { background: #CCCCCC; }

.top-level-menu
{
    list-style: none;
    padding: 0;
    margin: 0;
}

.top-level-menu > li
{
    position: relative;
    float: left;
    height: 30px;
    width: 100px;
    background: #999999;
}
.top-level-menu > li:hover { background: #CCCCCC; }

.top-level-menu li:hover > ul
{
    /* On hover, display the next level's menu */
    display: inline;
}


/* Menu Link Styles */

.top-level-menu a /* Apply to all links inside the multi-level menu */
{
    font: bold 14px Arial, Helvetica, sans-serif;
    color: #FFFFFF;
    text-decoration: none;
    padding: 0 0 0 10px;

    /* Make the link cover the entire list item-container */
    display: block;
    line-height: 30px;
}
.top-level-menu a:hover { color: #000000; }
</style>

检查我的菜单，其中没有箭头，其中li有ul

Answer 1

因此CSS中没有父选择器，但是当你用jQuery标记它时，我们可以使用：has（）选择器做同样的行为。基本上，如果LI el包含UL，我们应该假设UL是一个子菜单，我将添加＆＃39; js-has-a-submenu＆＃39;我们用于菜单项的锚点类。我用＆＃39; js - ＆＃39;做了前缀。只是为了反映它不是一个静态应用的类，但我们只能通过js使用。

这里的代码实际上是从我在提交中引用的菜单示例中获取的，但后来我注意到他们将向下箭头硬编码到菜单中，这实际上打破了你的＃39根据我的理解，重新尝试做。所以我删除了向下箭头，并使用jQuery来应用该类。要了解菜单本身，请继续阅读 this ，因为我认为它确实很好（不是粉红色的粉丝，而是它的css）。

＆＃13;

$("li:has(ul)").find("a:eq(0)").addClass("js-has-a-submenu");

＆＃13;

body {
  background: #333;
}

.clearfix:after {
  display: block;
  clear: both;
}


/*----- Menu Outline -----*/

.menu-wrap {
  width: 100%;
  box-shadow: 0px 1px 3px rgba(0, 0, 0, 0.2);
  background: #3e3436;
}

.menu {
  width: 1000px;
  margin: 0px auto;
}

.menu li {
  margin: 0px;
  list-style: none;
  font-family: 'Ek Mukta';
}

.menu a {
  text-decoration:none;
  transition: all linear 0.15s;
  color: #919191;
}

.menu li:hover > a,
.menu .current-item > a {
  text-decoration: none;
  color: #be5b70;
}

.menu .arrow {
  font-size: 11px;
  line-height: 0%;
}


/*----- Top Level -----*/

.menu > ul > li {
  float: left;
  display: inline-block;
  position: relative;
  font-size: 19px;
}

.menu > ul > li > a {
  padding: 10px 40px;
  display: inline-block;
  text-shadow: 0px 1px 0px rgba(0, 0, 0, 0.4);
}

.menu > ul > li:hover > a,
.menu > ul > .current-item > a {
  background: #2e2728;
}


/*----- Bottom Level -----*/

.menu li:hover .sub-menu {
  z-index: 1;
  opacity: 1;
}

.sub-menu {
  width: 160%;
  padding: 5px 0px;
  position: absolute;
  top: 100%;
  left: 0px;
  z-index: -1;
  opacity: 0;
  transition: opacity linear 0.15s;
  box-shadow: 0px 2px 3px rgba(0, 0, 0, 0.2);
  background: #2e2728;
}

.sub-menu li {
  display: block;
  font-size: 16px;
}

.sub-menu li a {
  padding: 10px 30px;
  display: block;
}

.sub-menu li a:hover,
.sub-menu .current-item a {
  background: #3e3436;
}

.js-has-a-submenu::after {
     content: " \2193";
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="menu-wrap">
  <nav class="menu">
    <ul class="clearfix">
      <li><a href="#">Home</a></li>
      <li>
        <a href="#">Movies </a>

        <ul class="sub-menu">
          <li><a href="#">In Cinemas Now</a></li>
          <li><a href="#">Coming Soon</a></li>
          <li><a href="#">On DVD/Blu-ray</a></li>
          <li><a href="#">Showtimes &amp; Tickets</a></li>
        </ul>
      </li>
      <li><a href="#">T.V. Shows</a></li>
      <li><a href="#">Photos</a></li>
      <li><a href="#">Site Help</a></li>
    </ul>
  </nav>
</div>

＆＃13;

Answer 2

如果你不隐藏ul，但李？然后你可以使用:: before来让css在你的ul之前插入一个小箭头。

请查看我的小提琴https://jsfiddle.net/dL758uba/

/* Menu Styles */

ul {display: inline;}

ul.third-level-menu::before {
content: '-';
position: relative;
left: -200px;
top: 10px;
}

ul::before {
content: '-';
position: relative;
left: 0px;
top: -20px;
}

.third-level-menu
{
    position: absolute;
    top: 0;
    right: -220px;
    width: 220px;
    list-style: none;
    padding: 0;
    margin: 0;

}

.third-level-menu > li
{
    height: 30px;
    background: #999999;
    display: none;
}
.third-level-menu > li:hover { background: #CCCCCC; }

.second-level-menu
{
    position: absolute;
    top: 30px;
    left: 0;
    width: 200px;
    list-style: none;
    padding: 0;
    margin: 0;

}

.second-level-menu > li
{
    position: relative;
    height: 30px;
    background: #999999;
    display: none;
}
.second-level-menu > li:hover { background: #CCCCCC; }

.top-level-menu
{
    list-style: none;
    padding: 0;
    margin: 0;
}

.top-level-menu > li
{
    position: relative;
    float: left;
    height: 30px;
    width: 100px;
    background: #999999;
}
.top-level-menu > li:hover { background: #CCCCCC; }

.top-level-menu li:hover > ul >li
{
    /* On hover, display the next level's menu */
    display: block;
}


/* Menu Link Styles */

.top-level-menu a /* Apply to all links inside the multi-level menu */
{
    font: bold 14px Arial, Helvetica, sans-serif;
    color: #FFFFFF;
    text-decoration: none;
    padding: 0 0 0 10px;

    /* Make the link cover the entire list item-container */
    display: block;
    line-height: 30px;
}
.top-level-menu a:hover { color: #000000; }

这有点粗糙，但我认为它会帮助你朝着正确的方向前进。

CSS-ckeck并添加右箭头，其中li有ul

2 个答案: