为什么切换功能不能在移动视图的主页上工作?

Question

我试图创建一个移动友好的网站。我几乎完成，但切换菜单的移动视图是不工作的主页。当我在主页上切换菜单不工作。如果我打开其他页面或菜单，那么切换功能正在工作。我不知道我错过了什么。这里我分享index.html页面代码，CSS和JavaScript代码。

function myFunction() {
var x = document.getElementById("myTopnav");
if (x.className === "topnav") {
x.className += " responsive";
} else {
x.className = "topnav";
}
}

.topnav {
overflow: hidden;
background-color: #6EAD50;
}
.topnav a {
float: left;
display: block;
color: #f2f2f2;
text-align: center;
padding: 14px 16px;
text-decoration: none;
font-size: 16px;
letter-spacing: 2px;
}
.topnav a:visited {
color: #ffffff;
}
.topnav .icon {
display: none;
}
.dropdown {
float: left;
overflow: hidden;
}
.dropdown .dropbtn {
font-size: 16px;
border: none;
outline: none;
color: white;
padding: 17px 17px;
background-color: inherit;
font-family: inherit;
margin: 0;
letter-spacing: 2px;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #373538;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
z-index: 1;
}
.dropdown-content a {
float: none;
color: #e3cc67fc;
padding: 12px 16px;
text-decoration: none;
display: block;
text-align: left;
}
.topnav a:hover,
.dropdown:hover .dropbtn {
background-color: #e3cc67fc;
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;
}
}

<div class="topnav" id="myTopnav">
<a href="{$config{base_url}}">Home</a>
<a href="{$config{base_url}}/help/index.html">Help</a>
<div class="dropdown">
<button class="dropbtn">Browse 
<i class="fa fa-caret-down"></i>
</button>
<div class="dropdown-content">
<a href="{$config{base_url}}/view/year/">Years</a>
<a href="{$config{base_url}}/view/subjects/">Subjects</a>
<a href="{$config{base_url}}/view/divisions/">Divisions</a>
<a href="{$config{base_url}}/view/creators/">Authors</a>
<a href="{$config{base_url}}/view/indexdbase/">Index Databases</a>
<a href="{$config{base_url}}/view/type/">Document Type</a>
</div>
</div>
<a href="{$config{base_url}}/information.html">About</a>
<a href="{$config{base_url}}/policies.html">Policies</a>
<a href="javascript:void(0);" style="font-size:15px;" class="icon" onclick="myFunction()">&#9776;</a>
</div>

Answer 1

试试这是你的Javascript文件

function myFunction() {
var x = document.getElementById("myTopnav");
if (x.className === "topnav") {
x.className += " responsive";
} else {
x.className = "topnav";
}
}

你可以使用

const navToggle = () => document.querySelector(".topnav").classList.toggle("responsive");

Toggle函数将执行其名称所表示的相同操作。如果你的元素有你选择的任何类，假设响应然后它会删除它，否则会添加它。