这是我的代码:
<div class="dropdown">
<button type="button" class="navbar-toggle1 " data-toggle="dropdown" data-target="#navbar" aria-expanded="true" aria-controls="rep_options">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<i class="fa fa-bars" aria-hidden="true" style=" font-size: 27px;"></i>
</button>
<ul class="dropdown-menu" style="margin-top: 8%; margin-left: 91%;">
<li><a href="#">HTML</a></li>
<li><a href="#">CSS</a></li>
<li><a href="#">JavaScript</a></li>
</ul>
</div>
</div>
我的菜单没有显示按钮。当菜单在右侧时,按钮位于左侧
答案 0 :(得分:0)
<header id="header" class="active">
header
</header>
<button id="button">Toggle</button>
<style>
header{
display:none;
border:solid 1px #F00;
height: 50px;
}
header.active{
display:block;
}
</style>
<script>
var button = document.getElementById("button");
var header = document.getElementById("header");
button.onclick = function (){
header.classList.toggle("active");
};
</script>
答案 1 :(得分:0)
您可能没有为引导程序包含js文件。在您的文件中包含此链接,然后重试。
a=sqrt(x*x+y*y)/r