功能描述
点击导航跳到对应模块的起始位置，并且高亮点击的导航；
滚动到相应的模块时，对应的导航也自动高亮；
效果展示
注意事项
- 一定要明确哪个是要滚动的盒子；
- 滚动的高度要减去导航栏的高度；
- 当前在导航1，点击导航4时，会出现导航2、导航3和导航4依次高亮的现象，定义变量判断当前为点击时不监听滚动事件即可；
isScroll.value = false
核心代码
onMounted(() => {
nextTick(() => {
// 监听滚动的盒子的滚动事件
document.getElementById('scrollBox').addEventListener("scroll", onScroll);
})
})
onBeforeUnmount(() => {
document.getElementById('scrollBox').removeEventListener('scroll', onScroll)
})
const scrollToAnchor = (id, index) => {
activeIndex.value = index
var anchor = document.getElementById(id);
var scrollBox = document.getElementById('scrollBox')
nextTick(() => {
scrollBox.scrollTo({
top: anchor.offsetTop - 30,
behavior: 'smooth'
});
})
isScroll.value = false
// 点击时暂停页面的滚动监听事件，防止点击时导航高亮出现走马灯效果；
// 此处的定时器存在缺陷，点击完2秒之内滚动还是会偶现走马灯现象；
let timeId = '';
clearTimeout(timeId);
timeId = setTimeout(() => {
isScroll.value = true;
}, 2000);
};
// 滚动监听器
const onScroll = ()=> {
if(!isScroll.value) return
// 获取所有锚点元素
const navContents = document.querySelectorAll('.container .section')
// 所有锚点元素的 offsetTop
const offsetTopArr = []
navContents.forEach(item => {
offsetTopArr.push(item.offsetTop-30)
})
// 获取当前文档流的 scrollTop
const scrollTop = document.getElementById('scrollBox').scrollTop
// 定义当前点亮的导航下标
let navIndex = 1
for (let n = 1; n <= offsetTopArr.length; n++) {
// 如果 scrollTop 大于等于第 n 个元素的 offsetTop 则说明 n-1 的内容已经完全不可见
// 那么此时导航索引就应该是 n 了
if (scrollTop >= offsetTopArr[n-1]) {
navIndex = n
}
}
// 把下标赋值给 vue 的 data
activeIndex.value = navIndex
}
完整代码
<template>
<div class="box" id="scrollBox" v-loading="loading">
<div class="fixed-box">
<div v-for="(i) in defaultTabs" :class="{active_anchor: activeIndex === i}">
<a @click="scrollToAnchor(`section${i}`, i)">
<span v-if="i == 1">导航1</span>
<span v-if="i == 2">导航2</span>
<span v-if="i == 3">导航3</span>
<span v-if="i == 4">导航4</span>
<span v-if="i == 5">导航5</span>
</a>
</div>
</div>
<div class="container" id="printcontent">
<div class="section" id="section1">
<h3>日历</h3>
<el-calendar v-model="value" />
</div>
<div class="section" id="section2">
<h3>带边框列表</h3>
<el-descriptions class="margin-top" title="" :column="4" border>
<template v-for="i in 4">
<el-descriptions-item label="Username">kooriookami</el-descriptions-item>
<el-descriptions-item label="Telephone">18100000000</el-descriptions-item>
<el-descriptions-item label="Place" :span="2">Suzhou</el-descriptions-item>
<el-descriptions-item label="Remarks">123123</el-descriptions-item>
<el-descriptions-item label="Username">一一一</el-descriptions-item>
<el-descriptions-item label="Remarks">123123</el-descriptions-item>
<el-descriptions-item label="Remarks">-</el-descriptions-item>
<el-descriptions-item label="Remarks">-</el-descriptions-item>
<el-descriptions-item label="Remarks">-</el-descriptions-item>
</template>
</el-descriptions>
</div>
<div class="section" id="section3">
<h3>普通表格</h3>
<el-table :data="tableData" style="width: 100%">
<el-table-column prop="date" label="Date" width="180" />
<el-table-column prop="name" label="Name" width="180" />
<el-table-column prop="address" label="Address" />
</el-table>
</div>
<div class="section" id="section4">
<h3>普通卡片</h3>
<el-card class="box-card">
<template #header>
<div class="card-header">
<span>Card name</span>
<el-button class="button" text>Operation button</el-button>
</div>
</template>
<div v-for="o in 10" :key="o" class="text item">{{ 'List item ' + o }}</div>
<template #footer>Footer content</template>
</el-card>
</div>
</div>
</div>
</template>
<script setup>
import { onMounted, ref, nextTick, onBeforeUnmount } from 'vue'
const loading = ref(false)
const value = ref(new Date())
const defaultTabs = ref([1, 2, 3, 4, 5])
const activeIndex = ref(1)
const isScroll = ref(true) // 点击导航栏时，暂时停止监听页面滚动
const tableData = [
{
date: '2016-05-03',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-02',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-04',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-01',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-04',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-01',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-04',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-01',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-04',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-01',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-04',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
{
date: '2016-05-01',
name: 'Tom',
address: 'No. 189, Grove St, Los Angeles',
},
]
onMounted(() => {
nextTick(() => {
document.getElementById('scrollBox').addEventListener("scroll", onScroll);
})
})
onBeforeUnmount(() => {
document.getElementById('scrollBox').removeEventListener('scroll', onScroll)
})
const scrollToAnchor = (id, index) => {
activeIndex.value = index
var anchor = document.getElementById(id);
var scrollBox = document.getElementById('scrollBox')
nextTick(() => {
scrollBox.scrollTo({
top: anchor.offsetTop - 30,
behavior: 'smooth'
});
})
// 点击时暂停页面的滚动监听事件，防止点击时导航高亮出现走马灯效果；
// 此处的定时器存在缺陷，点击完2秒之内滚动还是会偶现走马灯现象；
isScroll.value = false
let timeId = '';
clearTimeout(timeId);
timeId = setTimeout(() => {
isScroll.value = true;
}, 2000);
};
// 滚动监听器
const onScroll = ()=> {
if(!isScroll.value) return
// 获取所有锚点元素
const navContents = document.querySelectorAll('.container .section')
// 所有锚点元素的 offsetTop
const offsetTopArr = []
navContents.forEach(item => {
offsetTopArr.push(item.offsetTop-30)
})
// 获取当前文档流的 scrollTop
const scrollTop = document.getElementById('scrollBox').scrollTop
// 定义当前点亮的导航下标
let navIndex = 1
for (let n = 1; n <= offsetTopArr.length; n++) {
// 如果 scrollTop 大于等于第 n 个元素的 offsetTop 则说明 n-1 的内容已经完全不可见
// 那么此时导航索引就应该是 n 了
if (scrollTop >= offsetTopArr[n-1]) {
navIndex = n
}
}
// 把下标赋值给 vue 的 data
activeIndex.value = navIndex
}
</script>
<style scoped lang="scss">
.box{
// width: 98%;
margin: auto;
height: 100%;
overflow: auto;
}
.fixed-box{
width: calc(100% - 200px);
background: white;
position: fixed;
top: 84px;
display: flex;
justify-content: space-between;
align-items: center;
z-index: 99;
padding: 5px 30px;
box-sizing: border-box;
box-shadow: 1px 1px 1px #ccc;
span {
padding: 0 10px;
list-style: none;
}
}
.container {
padding-top: 15px;
position: relative;
}
.section {
margin: 20px 0;
}
:deep(.el-tabs ){
--el-tabs-header-height: 50px;
}
.active_anchor {
color: #409eff;
}
</style>
