<!DOCTYPE html>
<html>
<head>
<meta charset="gb2312">
<style>
.dropbtn {
background-color: #4CAF50;
color: white;
padding: 10px;
font-size: 16px;
border: none;
cursor: pointer;
}
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min- 160px;
overflow: auto;
top:30px;
z-index: 1;
}
.dropdown-content a {
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
}
.show {display:block;}
</style>
<script>
/* 点击按钮，下拉菜单在 显示/隐藏 之间切换 */
function myFunction() {
document.getElementById("myDropdown").classList.toggle("show");
}
// 点击下拉菜单意外区域隐藏
window.onclick = function(event) {
if (!event.target.matches('.dropbtn')) {
var dropdowns = document.getElementsByClassName("dropdown-content");
var i;
for (i = 0; i < dropdowns.length; i++) {
var openDropdown = dropdowns[i];
if (openDropdown.classList.contains('show')) {
openDropdown.classList.remove('show');
}
}
}
}
</script>
</head>
<body>
<div class="dropdown">
<a onclick="myFunction()" ontouch="myFunction()" class="dropbtn">导航</a>
<div id="myDropdown" class="dropdown-content">
<a href="#home">Home</a>
<a href="#about">About</a>
<a href="#contact">Contact</a>
</div>
</div>
</body>
</html>