下拉菜单

Tutorial: DOM操作 Category: JS Published: 2026-04-07 13:58:26 Views: 20 Likes: 0 Comments: 0
<!DOCTYPE html>
<html lang="en">
  <head>
    <style>
      * {
        margin: 0;
        padding: 0;
      }

      li {
        list-style-type: none;
      }

      a {
        text-decoration: none;
        font-size: 14px;
      }

      .nav {
        margin: 100px;
      }

      .nav > li {
        position: relative;
        float: left;
        width: 80px;
        height: 41px;
        text-align: center;
      }

      .nav li a {
        display: block;
        width: 100%;
        height: 100%;
        line-height: 41px;
        color: #333;
      }

      .nav > li > a:hover {
        background-color: #eee;
      }

      .nav ul {
        display: none; /* 控制显示在这里 */
        position: absolute;
        top: 41px;
        left: 0;
        width: 100%;
        border-left: 1px solid #fecc5b;
        border-right: 1px solid #fecc5b;
      }

      .nav ul li {
        border-bottom: 1px solid #fecc5b;
      }

      .nav ul li a:hover {
        background-color: #fff5da;
      }
    </style>
  </head>

  <body>
    <ul class="nav">
      <li>
        <a href="#">微博</a>
        <ul>
          <li>
            <a href="">私信</a>
          </li>
          <li>
            <a href="">评论</a>
          </li>
          <li>
            <a href="">@我</a>
          </li>
        </ul>
      </li>

      <li>
        <a href="#">微博</a>
        <ul>
          <li>
            <a href="">私信</a>
          </li>
          <li>
            <a href="">评论</a>
          </li>
          <li>
            <a href="">@我</a>
          </li>
        </ul>
      </li>

      <li>
        <a href="#">微博</a>
        <ul>
          <li>
            <a href="">私信</a>
          </li>
          <li>
            <a href="">评论</a>
          </li>
          <li>
            <a href="">@我</a>
          </li>
        </ul>
      </li>

      <li>
        <a href="#">微博</a>
        <ul>
          <li>
            <a href="">私信</a>
          </li>
          <li>
            <a href="">评论</a>
          </li>
          <li>
            <a href="">@我</a>
          </li>
        </ul>
      </li>
    </ul>

    <script>
      // 1. 获取元素
      var nav = document.querySelector(".nav");
      var lis = nav.children; // 得到4个小li

      // 2.循环注册事件
      for (var i = 0; i < lis.length; i++) {
        lis[i].onmouseover = function () {
          this.children[1].style.display = "block";
        };
        lis[i].onmouseout = function () {
          this.children[1].style.display = "none";
        };
      }
    </script>
  </body>
</html>