html - 我的下拉菜单不起作用

Question

我的下拉菜单无法正常工作，但是直到昨天才出现，我无法弄清楚出了什么问题，我已经仔细检查了代码，所以

#apDiv2 {
  position: fixed;
  width: 100%;
  height: auto;
  float: none;
  z-index: 6;
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333333;
  z-index: 6
}

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

li {
  float: left;
  width: 25%;
  text-align: center;
}

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);
  z-index: 1;
}

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

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

.dropdown:hover .dropdown-content {
  display: block;
}

<div id="apDiv2">
  <ul>
    <li><a href="homeA2.html">HOME</a></li>
    <li class="dropdown">
      <a href="javascript:void(0)" class="dropbtn">WORLD WAR 1</a>
      <div class="dropdown-content">
        <a href="HOWITBEGANA2.html">HOW IT BEGAN AND ENDED</a>
        <a href="SOILDERSLIFEA2.html">A SOLIDERS LIFE</a>
        <a href="WOMENSJOBA2.html">A WOMENS JOB</a>
      </div>
      <li class="dropdown">
        <a href="javascript:void(0)" class="dropbtn">NOTABLE FIGURES</a>
        <div class="dropdown-content">
          <a href="NotableFigures1A2.html">NOTABLE FIGURES PART 1</a>
          <a href="NotableFigures2A2.html">NOTABLE FIGURES PART 2</a></div>
        <li><a href="CommentsA2.html">COMMENTS AND QUETIONS</a></li>
  </ul>
</div>

Answer 1

从 #apDiv2 中移除 overflow: hidden;:

#apDiv2 {
  position: fixed;
  width: 100%;
  height: auto;
  float: none;
  z-index: 6;
  list-style-type: none;
  margin: 0;
  padding: 0;
  background-color: #333333;
  z-index: 6
}

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

li {
  float: left;
  width: 25%;
  text-align: center;
}

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);
  z-index: 1;
}

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

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

.dropdown:hover .dropdown-content {
  display: block;
}

<div id="apDiv2">
  <ul>
    <li><a href="homeA2.html">HOME</a></li>
    <li class="dropdown">
      <a href="javascript:void(0)" class="dropbtn">WORLD WAR 1</a>
      <div class="dropdown-content">
        <a href="HOWITBEGANA2.html">HOW IT BEGAN AND ENDED</a>
        <a href="SOILDERSLIFEA2.html">A SOLIDERS LIFE</a>
        <a href="WOMENSJOBA2.html">A WOMENS JOB</a>
      </div>
      <li class="dropdown">
        <a href="javascript:void(0)" class="dropbtn">NOTABLE FIGURES</a>
        <div class="dropdown-content">
          <a href="NotableFigures1A2.html">NOTABLE FIGURES PART 1</a>
          <a href="NotableFigures2A2.html">NOTABLE FIGURES PART 2</a></div>
        <li><a href="CommentsA2.html">COMMENTS AND QUETIONS</a></li>
  </ul>
</div>