html - 使div菜单按钮下拉

Question

如何仅使用 HTML 和 CSS 使 div 菜单按钮下拉并向其添加子菜单。

HTML:

<div class="right_menu"><a href="#" class="menu_button">Change Password</a>
        <a href="#" tabindex='1' class="sign_out_button">Sign Out</a>
        </div>

CSS:

 .sign_out_button{
        background-color: #2fa4e7;
        padding-top: 16px;
        padding-bottom: 16px;
        padding-left:10px;
        padding-right:10px;
        color: #FFF;
        float: left;
        text-decoration: none;
        }
    .sign_out_button:hover{background-color:#1892d7;}
    .sign_out_button a{color:#FFF; 
              text-decoration: none;}

Answer 1

这是另一种没有 javascript 的选择，它也能正常工作

<ul>
  <li>
    Menu
    <ul>
      <li>Submenu</li>
      <li>Submenu</li>
      <li>Submenu</li>
    </ul>
  </li>
</ul>

这是您的 html，插入您的页面。现在来了 CSS

ul {
  width:200px;
  text-align: left;
  display: inline;
  margin: 0;
  padding: 15px 4px 17px 0;
  list-style: none;
  -webkit-box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
  -moz-box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
}
ul li {width:200px;
  font: bold 12px/18px sans-serif;
  display: inline-block;
  margin-right: -4px;
  position: relative;
  padding: 15px 20px;
  background: #fff;
  cursor: pointer;
  -webkit-transition: all 0.2s;
  -moz-transition: all 0.2s;
  -ms-transition: all 0.2s;
  -o-transition: all 0.2s;
  transition: all 0.2s;
}
ul li:hover {
  background: #555;
  color: #fff;
}
ul li ul {
  padding: 0;
  position: absolute;
  top: 48px;
  left: 0;
  width:200px;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
  display: none;
  opacity: 0;
  visibility: hidden;
  -webkit-transiton: opacity 0.2s;
  -moz-transition: opacity 0.2s;
  -ms-transition: opacity 0.2s;
  -o-transition: opacity 0.2s;
  -transition: opacity 0.2s;
}
ul li ul li { 
  background: #555; 
  display: block; 
  color: #fff;
  text-shadow: 0 -1px 0 #000;
}
ul li ul li:hover { background: #666; }
ul li:hover ul {
  display: block;
  opacity: 1;
  visibility: visible;
}

这里有一个演示

https://jsfiddle.net/r50kbnq7/