使用 CSS 创建一个可悬停的下拉菜单。
将鼠标移至以下示例上:
创建一个下拉框,当用户将鼠标移到某个选项上时会出现该下拉框 元素。
<style>
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display:
none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
padding:
12px 16px;
z-index: 1;
}
.dropdown:hover
.dropdown-content {
display: block;
}
</style>
<div class="dropdown">
<span>Mouse over me</span>
<div class="dropdown-content">
<p>Hello World!</p>
</div>
</div>
自己尝试一下 →
<!DOCTYPE html>
<html>
<head>
<style>
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
padding: 12px 16px;
z-index: 1;
}
.dropdown:hover .dropdown-content {
display: block;
}
</style>
</head>
<body>
<h2>Hoverable Dropdown</h2>
<p>Move the mouse over the text below to open the dropdown content.</p>
<div class="dropdown">
<span>Mouse over me</span>
<div class="dropdown-content">
<p>Hello World!</p>
</div>
</div>
</body>
</html>
HTML) 使用任何元素打开下拉内容,例如A <span> 或 <button> 元素。
使用容器元素(如 <div>)创建下拉内容并添加 里面有你想要的任何东西。
将 <div> 元素包裹在元素周围以定位下拉内容 正确使用CSS。
CSS) .dropdown
类使用 position:relative
,当我们想要 下拉内容放置在下拉按钮的正下方(使用 position:absolute
)。
.dropdown-content
类保存实际的下拉内容。它隐藏于 默认,并将在悬停时显示(见下文)。请注意,min-width
设置为 160px。随意改变 这。 提示:如果您希望下拉内容的宽度为 与下拉按钮一样宽,将 width
设置为 100%(并将 overflow:auto
设置为 在小屏幕上启用滚动)。
我们没有使用边框,而是使用 CSS box-shadow
属性来制作 下拉菜单看起来像一张“卡片”。
:hover
选择器用于在用户移动鼠标时显示下拉菜单 将鼠标悬停在下拉按钮上。
创建一个下拉菜单,允许用户从列表中选择一个选项:
此示例与上一个示例类似,只是我们在下拉框中添加链接并设置它们的样式以适合样式化的下拉按钮:
<style>
/* Style The Dropdown Button */
.dropbtn {
background-color: #4CAF50;
color: white;
padding: 16px;
font-size: 16px;
border: none;
cursor: pointer;
}
/* The
container <div> - needed to position the dropdown content */
.dropdown {
position: relative;
display:
inline-block;
}
/* Dropdown Content (Hidden by Default) */
.dropdown-content {
display: none;
position:
absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow:
0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
/* Links inside the dropdown */
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
}
/* Change color of dropdown links on hover */
.dropdown-content a:hover {background-color: #f1f1f1}
/* Show the
dropdown menu on hover */
.dropdown:hover .dropdown-content {
display: block;
}
/* Change the background color of the dropdown
button when the dropdown content is shown */
.dropdown:hover .dropbtn {
background-color: #3e8e41;
}
</style>
<div class="dropdown">
<button class="dropbtn">Dropdown</button>
<div class="dropdown-content">
<a href="#">Link
1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</div>
自己尝试一下 →
<!DOCTYPE html>
<html>
<head>
<style>
.dropbtn {
background-color: #4CAF50;
color: white;
padding: 16px;
font-size: 16px;
border: none;
cursor: pointer;
}
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
}
.dropdown-content a:hover {background-color: #f1f1f1}
.dropdown:hover .dropdown-content {
display: block;
}
.dropdown:hover .dropbtn {
background-color: #3e8e41;
}
</style>
</head>
<body>
<h2>Dropdown Menu</h2>
<p>Move the mouse over the button to open the dropdown menu.</p>
<div class="dropdown">
<button class="dropbtn">Dropdown</button>
<div class="dropdown-content">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</div>
<p><strong>Note:</strong> We use href="#" for test links. In a real web site this would be URLs.</p>
</body>
</html>
如果您希望下拉菜单从右到左,而不是从左到右,请添加 right: 0;
.dropdown-content {
right: 0;
}
自己尝试一下 →
<!DOCTYPE html>
<html>
<head>
<style>
.dropbtn {
background-color: #4CAF50;
color: white;
padding: 16px;
font-size: 16px;
border: none;
cursor: pointer;
}
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
right: 0;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
}
.dropdown-content a:hover {background-color: #f1f1f1;}
.dropdown:hover .dropdown-content {
display: block;
}
.dropdown:hover .dropbtn {
background-color: #3e8e41;
}
</style>
</head>
<body>
<h2>Aligned Dropdown Content</h2>
<p>Determine whether the dropdown content should go from left to right or right to left with the left and right properties.</p>
<div class="dropdown" style="float:left;">
<button class="dropbtn">Left</button>
<div class="dropdown-content" style="left:0;">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</div>
<div class="dropdown" style="float:right;">
<button class="dropbtn">Right</button>
<div class="dropdown-content">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</div>
</body>
</html>
如何在下拉框中添加图像和其他内容。
将鼠标悬停在图像上:
自己尝试一下 →
<!DOCTYPE html>
<html>
<head>
<style>
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
.dropdown:hover .dropdown-content {
display: block;
}
.desc {
padding: 15px;
text-align: center;
}
</style>
</head>
<body>
<h2>Dropdown Image</h2>
<p>Move the mouse over the image below to open the dropdown content.</p>
<div class="dropdown">
<img src="img_5terre.jpg" alt="Cinque Terre" width="100" height="50">
<div class="dropdown-content">
<img src="img_5terre.jpg" alt="Cinque Terre" width="300" height="200">
<div class="desc">Beautiful Cinque Terre</div>
</div>
</div>
</body>
</html>
如何在导航栏中添加下拉菜单。
自己尝试一下→
<!DOCTYPE html>
<html>
<head>
<style>
ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #333;
}
li {
float: left;
}
li a, .dropbtn {
display: inline-block;
color: white;
text-align: center;
padding: 14px 16px;
text-decoration: none;
}
li a:hover, .dropdown:hover .dropbtn {
background-color: red;
}
li.dropdown {
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
text-align: left;
}
.dropdown-content a:hover {background-color: #f1f1f1;}
.dropdown:hover .dropdown-content {
display: block;
}
</style>
</head>
<body>
<ul>
<li><a href="#home">Home</a></li>
<li><a href="#news">News</a></li>
<li class="dropdown">
<a href="javascript:void(0)" class="dropbtn">Dropdown</a>
<div class="dropdown-content">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</li>
</ul>
<h3>Dropdown Menu inside a Navigation Bar</h3>
<p>Hover over the "Dropdown" link to see the dropdown menu.</p>
</body>
</html>