我正在创建一个 HTML 网页，其中包含一个带下拉菜单的粘性导航栏。但是，当我创建一个时，下拉菜单在粘性导航栏中不起作用，反之亦然。下面是两个代码的结果截图。
*image with dropdown menu but without sticky navbar
*image with sticky navbar but without dropdown menu
下面是“带有下拉菜单但没有粘性导航栏的图像”的代码
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font- awesome/4.7.0/css/font-awesome.min.css">
<style>
body {margin:0;font-family:Arial}
.topnav {
overflow: hidden;
background-color: #333;
}
.topnav a {
list-style-type: none;
float: left;
display: block;
color: #f2f2f2;
text-align: center;
padding: 14px 16px;
text-decoration: none;
font-size: 17px;
position: sticky;
}
.active {
background-color: #04AA6D;
color: white;
}
.topnav .icon {
display: none;
}
.dropdown {
float: left;
overflow: hidden;
}
.dropdown .dropbtn {
font-size: 17px;
border: none;
outline: none;
color: white;
padding: 14px 16px;
background-color: inherit;
font-family: inherit;
margin: 0;
}
.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 {
float: none;
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
text-align: left;
}
.topnav a:hover, .dropdown:hover .dropbtn {
background-color: #555;
color: white;
}
.dropdown-content a:hover {
background-color: #ddd;
color: black;
}
.dropdown:hover .dropdown-content {
display: block;
}
@media screen and (max-width: 600px) {
.topnav a:not(:first-child), .dropdown .dropbtn {
display: none;
}
.topnav a.icon {
float: right;
display: block;
}
}
@media screen and (max-width: 600px) {
.topnav.responsive {position: relative;}
.topnav.responsive .icon {
position: absolute;
right: 0;
top: 0;
}
.topnav.responsive a {
float: none;
display: block;
text-align: left;
}
.topnav.responsive .dropdown {float: none;}
.topnav.responsive .dropdown-content {position: relative;}
.topnav.responsive .dropdown .dropbtn {
display: block;
width: 100%;
text-align: left;
}
}
</style>
</head>
<body>
<div class="header">
<h2>Scroll Down</h2>
<p>Scroll down to see the sticky effect.</p>
</div>
<div class="topnav" id="myTopnav">
<a href="#home" class="active">Home</a>
<a href="#news">News</a>
<a href="#contact">Contact</a>
<div class="dropdown">
<button class="dropbtn">Dropdown
<i class="fa fa-caret-down"></i>
</button>
<div class="dropdown-content">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</div>
<a href="#about">About</a>
<a href="javascript:void(0);" style="font-size:15px;" class="icon" onclick="myFunction()">☰</a>
</div>
<div style="padding-left:16px">
<h2>Responsive Topnav with Dropdown</h2>
<p>Resize the browser window to see how it works.</p>
<p>Hover over the dropdown button to open the dropdown menu.</p>
</div>
<h3>Sticky Navigation Bar Example</h3>
<p>The navbar will <strong>stick</strong> to the top when you reach its scroll position.</p>
<p><strong>Note:</strong> Internet Explorer do not support sticky positioning and Safari requires a -webkit- prefix.</p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<script>
function myFunction() {
var x = document.getElementById("myTopnav");
if (x.className === "topnav") {
x.className += " responsive";
} else {
x.className = "topnav";
}
}
</script>
</body>
</html>
下面是“带有粘性导航栏但没有下拉菜单的图像”的代码
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font- awesome/4.7.0/css/font-awesome.min.css">
<style>
body {
font-size: 20px;
}
body {margin:0;}
ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #333;
position: -webkit-sticky; /* Safari */
position: sticky;
top: 0;
}
li {
float: left;
}
li a {
display: block;
color: white;
text-align: center;
padding: 16px 20px;
text-decoration: none;
}
li a:hover {
background-color: #111;
}
/*======================================================================*/
body {
background-color:white;
}
ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #38444d;
}
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;
}
footer {
text-align: center;
padding: 3px;
background-color: DarkSalmon;
color: white;
}
</style>
</head>
<body>
<div class="header">
<h2>Scroll Down</h2>
<p>Scroll down to see the sticky effect.</p>
</div>
<ul>
<li><a href="#home">Home</a></li>
<li><a href="#news">News</a></li>
<li class="dropdown">
<a href="javascript:void(1)" 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>Sticky Navigation Bar Example</h3>
<p>The navbar will <strong>stick</strong> to the top when you reach its scroll position.</p>
<p><strong>Note:</strong> Internet Explorer do not support sticky positioning and Safari requires a -webkit- prefix.</p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<p>Some text to enable scrolling. </p>
<footer>
<p>Author: Hege Refsnes<br>
<a href="mailto:hege@example.com">hege@example.com</a></p>
</footer>
</body>
</html>
请给我一些帮助，因为我是 html 和 css 的新手。
最佳答案
在第一个代码中，从导航栏中删除溢出属性，并为其添加一个最小高度，如下所示，
.topnav {
/* overflow: hidden; */
background-color: #333;
position: sticky;
top: 0;
min-height: 45px;
}
由于您在导航项中使用了 float 属性，因此可能会造成问题
工作代码Code
关于javascript - 如何使用 HTML 创建带有下拉菜单的粘性导航栏？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/72149891/