我正在寻找一些(可能很简单(建议，但在谷歌上似乎找不到。我有一个可悬停的下拉菜单，例如：
/* Dropdown Button */
.btn {
background-color: #D6182D;
color: white;
padding: 8px;
font-size: 16px;
border: none;
}
/* The container <div> - needed to position the dropdown content */
.dropdown {
position: relative;
display: inline-block;
border: 10px;
}
/* Dropdown Content (Hidden by Default) */
.dropdown-content {
display: none;
position: absolute;
background-color: #f1f1f1;
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: #ddd;
}
/* 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 .btn {
background-color: rgb(134, 30, 42);
}<center>
<div class="dropdown">
<a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Chose a month to display</a>
<div class="dropdown-content">
<a class="nav-link" href="/jan">
<font color="black">January 2018</font>
</a>
<a class="nav-link" href="/feb">
<font color="black">February 2018</font>
</a>
<a class="nav-link" href="/mar">
<font color="black">March 2018</font>
</a>
<a class="nav-link" href="/tot">
<font color="black">Total</font>
</a>
</div>
</div>
</center>基本上取自w3schools。。
现在，我想在有人点击后显示所选的选项，而不是"选择一个月来显示"。你们知道如何更改代码吗？
期待您的回答：-(
我对HTML进行了一些更改，使其更具语义，对于下拉文本，您可以尝试纯javascript。我希望，这将帮助你
对于旧价值，您可以将您的价值存储在某个地方，如本地存储
例如，我正在本地存储中保存旧的选定值。
const months = document.getElementsByClassName("dropdown-content");
if(localStorage.getItem("oldval")){
document.getElementById("dropdownMenuLink").innerHTML =
localStorage.getItem("oldval");
}
Array.from(months).map(month=>{
month.addEventListener("click",(e)=>{
let selectedValue = e.target.textContent;
document.getElementById("dropdownMenuLink").innerHTML =
selectedValue;
localStorage.setItem("oldval",selectedValue);
});
});
const months = document.getElementsByClassName("dropdown-content");
Array.from(months).map(month=>{
month.addEventListener("click",(e)=>{
e.preventDefault();
let selectedValue = e.target.textContent;
document.getElementById("dropdownMenuLink").innerHTML = selectedValue;
});
});/* Dropdown Button */
.btn {
background-color: #D6182D;
color: white;
padding: 8px;
font-size: 16px;
border: none;
min-width: 200px;
display:inline-block;
text-decoration:none;
}
/* The container <div> - needed to position the dropdown content */
.dropdown {
position: relative;
display: inline-block;
border: 10px;
}
/* Dropdown Content (Hidden by Default) */
.dropdown-content {
display: none;
position: absolute;
background-color: #f1f1f1;
min-width: 200px;
box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
z-index: 1;
list-style: none;
padding:0;
margin:0;
}
/* 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: #ddd;
}
/* 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 .btn {
background-color: rgb(134, 30, 42);
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<center>
<div class="dropdown">
<a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Chose a month to display</a>
<ul class="dropdown-content">
<li><a class="nav-link" href="/jan">
January 2018
</a></li>
<li><a class="nav-link" href="/feb">
February 2018
</a></li>
<li><a class="nav-link" href="/mar">
March 2018
</a></li>
<li><a class="nav-link" href="/tot">
Total
</a></li>
</ul>
</div>
</center>
</body>
</html>正如我所看到的，您正在使用<div>和<a>来实现下拉菜单，这一点都没有错，但不是html的正确方式。
阅读<select>和<option>标签，这将帮助您获得下拉效果，并且您可以在单击<option>标签时动态设置value。通过使用getElementById('id-of-element')
阅读此处的getElementById
此外，如果您希望在用户单击时进行重定向，您可以在<option>标记中使用<a>标记。
选择标签
希望这将帮助你，张贴任何疑问，如果你有将很乐意帮助你：-(