如果你想设置右浮动的下拉菜单内容方向是从右到左，而不是从左到右，可以添加以下代码 right: 0; - 在线编辑器

<!DOCTYPE html>
<html>
<head>
  <title>下拉菜单实例|蜜蜂教程(mifengjc.com)</title>
  <meta charset="utf-8">
  <style>
    .dropbtn {
      background-color: #4CAF50;
      color: white;
      padding: 16px;
      font-size: 16px;
      border: none;
      cursor: pointer;
    }

    .dropdown {
      position: relative;
      display: inline-block;
    }

    .dropdown-content {
      display: none;
      position: absolute;
      right: 0;
      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;
    }

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

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

    .dropdown:hover .dropbtn {
      background-color: #3e8e41;
    }
  </style>
</head>
<body>

  <h2>下拉内容的对齐方式</h2>
  <p>left 和 right 属性指定了下拉内容是从左到右或从右到左。</p>

  <div class="dropdown" style="float:left;">
    <button class="dropbtn">左</button>
    <div class="dropdown-content" style="left:0;">
      <a href="#">蜜蜂教程 1</a>
      <a href="#">蜜蜂教程 2</a>
      <a href="#">蜜蜂教程 3</a>
    </div>
  </div>

  <div class="dropdown" style="float:right;">
    <button class="dropbtn">右</button>
    <div class="dropdown-content">
      <a href="#">蜜蜂教程 1</a>
      <a href="#">蜜蜂教程 2</a>
      <a href="#">蜜蜂教程 3</a>
    </div>
  </div>

</body>
</html>
​x
 
<!DOCTYPE html>
<html>
<head>
  <title>下拉菜单实例|蜜蜂教程(mifengjc.com)</title>
  <meta charset="utf-8">
  <style>
    .dropbtn {
      background-color: #4CAF50;
      color: white;
      padding: 16px;
      font-size: 16px;
      border: none;
      cursor: pointer;
    }
​
    .dropdown {
      position: relative;
      display: inline-block;
    }
​
    .dropdown-content {
      display: none;
      position: absolute;
      right: 0;