Vue添加页面滚动事件实现菜单栏固定定位到页面上

Dear 丶 2023-10-04 19:06 59阅读 0赞

当页面没有滚动的时候，菜单栏是固定在logo下面的：

![943b013db68b47f3b503b53e0509783e.png][]

当页面滚动超过logo的高度时候，就让菜单栏固定定位到页面顶部：

![8309d6639cca42b0bc2754ff2b620ca6.png][]

代码实现：

<template>
      
      <div :class="{ navbar: true, totop: isTop }">
        <ul class="bar">
          <li>首页</li>
          <li>乐享生活</li>
          <li>硬核编程</li>
          <li>绚丽前端</li>
          <li>数据仓库</li>
          <li>数据仓库</li>
          <li>数据仓库</li>
          <li>数据仓库</li>
    
          <li class="search">
            <svg-icon icon-class="search" />
          </li>
        </ul>
      </div>
    </template>
    
    <script>
    export default {
      name: "navbar",
      data() {
        return {
          isTop: false,
        };
      },
      mounted() {
        window.addEventListener("scroll", this.scrollToTop, true);
      },
      destroyed() {
        window.removeEventListener("scroll", this.scrollToTop, true);
      },
      methods: {
        scrollToTop() {
          let scrollTop =
            window.pageYOffset ||
            document.documentElement.scrollTop ||
            document.body.scrollTop;
          //为了计算距离顶部的高度，当高度大于50显示回顶部图标，小于50则隐藏
          if (scrollTop > 60) {
            console.log("页面滚动超过60了");
            this.isTop = true;
          } else {
            console.log("页面没有超过50");
            this.isTop = false;
          }
        },
      },
    };
    </script>
    
    <style lang="scss">
    .navbar {
      width: 100%;
      height: 58px;
      background-color: #244469;
      box-shadow: 0px 3px 5px #ccc;
    }
    
    .totop {
      position: fixed;
      top: 0;
      z-index: 999;
    }
    
    .bar {
      width: 1226px;
      height: 58px;
      margin: 0 auto;
      padding: 0;
      line-height: 58px;
      font-size: 18px;
      font-weight: 500;
    
      li {
        float: left;
        width: auto;
        padding: 0 20px;
        min-width: 75px;
        color: white;
        background-color: #244469;
    
        &:hover {
          background-color: #246469;
        }
      }
    
      .search {
        min-width: 25px;
        float: right;
      }
    }
    </style>

补充知识点：

![226b4c6bd10649999e4d0d36cdc25e5e.png][]

[943b013db68b47f3b503b53e0509783e.png]: https://img-blog.csdnimg.cn/943b013db68b47f3b503b53e0509783e.png
[8309d6639cca42b0bc2754ff2b620ca6.png]: https://img-blog.csdnimg.cn/8309d6639cca42b0bc2754ff2b620ca6.png
[226b4c6bd10649999e4d0d36cdc25e5e.png]: https://img-blog.csdnimg.cn/226b4c6bd10649999e4d0d36cdc25e5e.png