javascript - 如何让我的下拉菜单出现/对齐

Question

所以我正在制作一个简单的网页，但我无法让我的下拉菜单正常工作。此时甚至不再出现，当它出现在水平线而不是垂直线时。

因为它不显示下拉列表。我错过了什么？我有不需要的额外东西吗？

function myFunction() {
document.getElementById("myDropdown").classList.toggle("show");
 }
 window.onclick = function(e) {
if (!e.target.matches('.dropbtn')) {

var dropdowns = document.getElementsByClassName("dropdown-content");
for (var d = 0; d < dropdowns.length; d++) {
  var openDropdown = dropdowns[d];
  if (openDropdown.classList.contains('show')) {
    openDropdown.classList.remove('show');
   }
  }
 }
}

   ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
    }

    li {
    float: left;
    }

    li a, .dropbtn {
    display: inline-block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    }

    li a:hover, .dropdown:hover .dropbtn {
    background-color: red;
    }

    li.dropdown {
       display: inline-block;
    }

    .dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    }

    .dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
    }

    .dropdown-content a:hover {background-color: #f1f1f1}

    .show {display:block;}

    <nav>
	  <ul>
		<li><a href='front.html'>Home</a></li>
		<li><a href='intro.html'>Intro</a></li>
		<li><a href='how.html'>How it Works</a></li>
		<li><a href='best.html'>Using it</a></li>
		<li class ="dropdown">
			<a href="javascript:void(0)" class="dropbtn" 
			onclick="myFunction()">Examples</a>
				<ul class="dropdown-content" id="myDropdown">
				<div class="dropdown-content" id="myDropdown">
					<li><a href='saga.html'>SAGA</a></li>
					<li><a href='portfolio.html'>Portfolio Optimization</a></li>
					<li><a href='circuits.html'>Evolved Circuits</a></li>
				</div>
				</ul>
		</li>
		<li><a href='about.html'>References</a></li>
	</ul>
   </nav>

Answer 1

我刚刚删除了 ul 标签中的 div 并覆盖了下拉列表的 li 标签样式(删除了 float: left fot that li 标签)

function myFunction() {
document.getElementById("myDropdown").classList.toggle("show");
 }
 window.onclick = function(e) {
if (!e.target.matches('.dropbtn')) {

var dropdowns = document.getElementsByClassName("dropdown-content");
for (var d = 0; d < dropdowns.length; d++) {
  var openDropdown = dropdowns[d];
  if (openDropdown.classList.contains('show')) {
    openDropdown.classList.remove('show');
   }
  }
 }
}

   ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
    }

    li {
    float: left;
    }
    .dropdown-content li {
     float: none !important; 
    }

    li a, .dropbtn {
    display: inline-block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    }

    li a:hover, .dropdown:hover .dropbtn {
    background-color: red;
    }

    li.dropdown {
       display: inline-block;
    }

    .dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    }

    .dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
    }

    .dropdown-content a:hover {background-color: #f1f1f1}

    .show {display:block;}

    <nav>
	  <ul>
		<li><a href='front.html'>Home</a></li>
		<li><a href='intro.html'>Intro</a></li>
		<li><a href='how.html'>How it Works</a></li>
		<li><a href='best.html'>Using it</a></li>
		<li class ="dropdown">
			<a href="javascript:void(0)" class="dropbtn" 
			onclick="myFunction()">Examples</a>
				<ul class="dropdown-content" id="myDropdown">
					<li><a href='saga.html'>SAGA</a></li>
					<li><a href='portfolio.html'>Portfolio Optimization</a></li>
					<li><a href='circuits.html'>Evolved Circuits</a></li>
				</div>
				</ul>
		</li>
		<li><a href='about.html'>References</a></li>
	</ul>
   </nav>