Question

function ServicesMenu() {
    document.getElementsByClassName("services-cont")[0].classList.toggle("showS");
}

@charset "UTF-8";

*{padding:0;margin:0;}

body{min-width:300px; margin: 0px; padding: 0px; background:#f8f8f8 }

.wrapper {
	max-width: 980px;
	height:2000px;
	margin: 0px auto;
	position: relative; 
	background-color: #fff;
}

header{
	width:980px;
	height:105px;
	background:  #e60000;
}

ul.navbar {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
	top:63px;
	right:60px;
    width: 560px;
	display: block;
	position: absolute;
}

ul.navbar li {
	display:inline-block;
	Margin-left:15px;
	background: black;
}

ul.navbar li a {
    display: inline-block;
    color: #f2f2f2;
    text-align: center;
    padding: 5px 15px;
    text-decoration: none;
    font-size: 17px;
}

ul.navbar li a:hover {background-color: #660000;}

.services-cont{display: none;}

.services-cont.showS {	
	list-style-type: none;
	display: block;
	background-color: #707070 ;
	}

.services-cont.showS li {
    float: none;
    display: inline;
	height:0;
	border:none;
  }
  
.services-cont.showS li a {
    display: block;
    text-align: left;

  }

<!DOCTYPE html>

<html lang="en">

<head>

<meta charset="utf-8">

<link rel="stylesheet" type="text/css" href="menustyle.css">

<meta name="viewport" content="width=device-width, maximum-scale=1.0, minimum-scale=1.0, initial-scale=1" />

<script src="MenuFunc.js"></script>

<Title>Menu</title>

</head>

<body>
<div class="wrapper">
	
<header>

	</header>
	
	<ul class="navbar">

		<li><a href="#home">Home</a></li>
		<li><a href="javascript:void(0);" onclick="ServicesMenu()">Services</a>
			<ul class="services-cont">
				<li><a href="#">Service 1</a></li>      
				<li><a href="#">Service 2</a></li>
				<li><a href="#">Service 3</a></li>
			</ul>
		</li>
		<li><a href="#contact">Contact</a></li>

	</ul>

</div>	

</body>
</html>

但是，父{4}}显示在顶部，下面是嵌套列表，父列表的其余<li>与子列表的末尾对齐。

如何在直线中水平对齐父项列表项主页，服务和联系？

enter image description here

Answer 1

说明

您需要为嵌套的<li>标记添加以下两行CSS代码。

ul li ul {    
    position: absolute;
    top: auto;
}

将位置设置为绝对，将top设置为auto将在父标记下显示嵌套的ul。

代码

按下面的“运行代码段”按钮查看代码输出。

ul li {
  background: black;
  color: white;
  display: inline-block;
  width: 100px;
}
ul li ul {
  margin: 0px;
  padding: 0px;
  background: grey;
  /*YOU NEED THE TWO LINES BELOW*/
  position: absolute;
  top: auto;
}
ul li ul li {
  color: white;
  background: grey;
  display: block;
  width: 80px;
  padding: 10px;
}

<html>

<body>
  <ul>
    <li>
      Home
    </li>
    <li>
      Services
      <ul>
        <li>1</li>
        <li>2</li>
        <li>3</li>
      </ul>
    </li>
    <li>
      Contact
    </li>
  </ul>
</body>

</html>

Answer 2

说明

position: absolute和overflow: hidden属性存在干扰，不允许下拉列表正常显示。我在代码中对它们进行了评论，以便您可以看到。

您应该避免使用绝对定位，只需简单地嵌套标记即可达到相同的效果。例如，我将您的navbar嵌套在红色header内。

代码

按＆＃39;运行代码段＆＃39;按钮下方查看代码输出。

＆＃13;

* {
  padding: 0;
  margin: 0;
}
body {
  min-width: 300px;
  margin: 0px;
  padding: 0px;
  background: #f8f8f8
}
.wrapper {
  max-width: 980px;
  height: 2000px;
  margin: 0px auto;
  /*position: relative;*/
  background-color: #fff;
}
header {
  padding: 20px;
  width: 980px;
  height: 30px;
  background: #e60000;
}
.navbar {
  list-style-type: none;
  margin: 0;
  padding: 0;
  /*overflow: hidden;*/
  top: 63px;
  right: 60px;
  width: 560px;
  display: block;
  /*position: absolute;*/
}
.navbar li {
  display: inline-block;
  Margin-left: 15px;
  background: black;
}
.navbar li a {
  display: inline-block;
  color: #f2f2f2;
  text-align: center;
  padding: 5px 15px;
  text-decoration: none;
  font-size: 17px;
}
.navbar li a:hover {
  background-color: #660000;
}
.navbar li ul {
  position: absolute;
  top: auto;
  list-style-type: none;
  display: none;
  background-color: #707070;
}
.navbar li ul li {
  float: none;
  display: inline;
  height: 0;
  border: none;
}
.navbar li ul li a {
  display: block;
  text-align: left;
}
.navbar li:hover>ul {
  display: block;
}

＆＃13;

<!DOCTYPE html>

<html lang="en">

  <head>
  <Title>Menu</title>
</head>

<body>
  <div class="wrapper">
    <header>
      <ul class="navbar">
        <li><a href="#home">Home</a>
        </li>
        <li><a href="#">Services</a>
          <ul>
            <li><a href="#">Service 1</a>
            </li>
            <li><a href="#">Service 2</a>
            </li>
            <li><a href="#">Service 3</a>
            </li>
          </ul>
        </li>
        <li><a href="#contact">Contact</a>
        </li>
      </ul>
    </header>
  </div>
</body>

</html>

＆＃13;

如何使嵌套列表出现在父列表项下面？

2 个答案:

说明

代码

说明

代码