function myFunction() {
var x = document.getElementById("myTopnav");
if (x.className === "topnav") {
x.className += " responsive";
} else {
x.className = "topnav";
}
}
body {margin:0;}
ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #333;
}
li {
float: left;
}
.topnav {
overflow: hidden;
background-color: #333;
}
.topnav a {
float: left;
display: block;
color: #f2f2f2;
text-align: center;
padding: 14px 16px;
text-decoration: none;
font-size: 17px;
}
.topnav a:hover {
background-color: #ddd;
color: black;
}
.topnav .icon {
display: none;
}
@media screen and (max-width: 600px) {
.topnav li:not(:first-child) {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;
}
}
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<ul class="topnav" id="myTopnav">
<li><a href="#home">Home</a></li>
<li><a href="#news">News</a></li>
<li><a href="#contact">Contact</a></li>
<li><a href="#about">About</a></li>
<li><a href="javascript:void(0);" style="font-size:15px;" class="icon" onclick="myFunction()">☰</a></li>
</ul>
<div style="padding-left:16px">
<h2>Responsive Topnav Example</h2>
<p>Resize the browser window to see how it works.</p>
</div>
</body>
</html>
在代碼當屏幕尺寸小於600px的主頁選項卡停留,其餘的應該是可以通過的漢堡包圖標應該在右下角顯示但它不起作用。 我做錯了什麼? 我應該做些什麼才能使其發揮作用? 請幫忙