需求
在使用el-table 时，表格高度自适应（不出现滚动条， 仅body有滚动条）；滚动到表头的位置时自动吸附在顶部。
实现方法/原理
1、通过监听滚动事件、获取表头的高度，位置，在特定的情况下修改el-table-header的style属性 2、由于考虑到使用keep-alive，所以每个表格组件都需要加一个唯一的class值，用于获取当前唯一的表格的dom 3、因为项目使用了vue2.0版本，考虑到便捷性，采用了mixins混入方案，只测试vue2.0，不建议使用全局混入 在线预览地址：lsz579.github.io/element-tab…
新建一个 table-sticky.js
/* 组件需要提供parent字段，指定表格的className（字符串） */
const rafThrottle = (fn) => {
let locked = false
return function (...args) {
if (locked) return
locked = true
window.requestAnimationFrame(_ => {
fn.apply(this, args)
locked = false
})
}
}
export default {
mounted() {
this.parent = 'table-panel'
this.containerDom = document.getElementsByClassName('app-container')
this.clearListener()
const timer = setTimeout(() => {
this.initFixedHeader()
clearTimeout(timer)
}, 300)
window.addEventListener('resize', this.resizeChange)
},
deactivated() {
this.clearListener()
},
beforeDestroy() {
this.clearListener()
// 取消监听窗口大小
window.removeEventListener('resize', this.resizeChange)
},
activated() {
this.initFixedHeader()
this.updateFixedRight()
window.addEventListener('resize', this.resizeChange)
const timer = setTimeout(() => {
const container = this.containerDom
if (container[0].scrollTop > 0) {
container[0].scrollTop = container[0].scrollTop + 2
}
clearTimeout(timer)
}, 1000)
},
methods: {
activatedReload() {
window.addEventListener('resize', this.resizeChange)
const timer = setTimeout(() => {
this.clearFixedStyle()
this.initFixedHeader()
}, 300)
this.timerList.push(timer)
},
reset() {
this.clearFixedStyle()
},
// 窗口大小变化时，初始化
resizeChange() {
this.headerDragend()
const timer = setTimeout(() => {
this.initFixedHeader()
clearTimeout(timer)
}, 300)
},
async initFixedHeader() {
if (this.parent) {
this.parentDom = document.getElementsByClassName(this.parent)
console.log('启动监听，页面：', this.parent, this.parentDom)
if (this.parentDom && this.parentDom.length !== 0) {
this.tableWidth = this.parentDom[0].querySelector('.el-table__header-wrapper').getBoundingClientRect().width
this.setScrollXWidth()
this.tableDom = this.parentDom[0].getElementsByClassName('el-table__header-wrapper')
this.scrollDom = document.querySelector('.app-container')
this.scrollDom.addEventListener('scroll', this.scrollEvent)
}
}
},
// 清空监听事件
clearListener() {
if (this.scrollDom) {
this.scrollDom.removeEventListener('scroll', this.scrollEvent)
window.removeEventListener('resize', this.resizeChange)
this.clearFixedStyle()
// console.log('卸载监听,页面：', this.parent)
this.timerList.forEach(key => {
clearTimeout(key)
})
}
},
// 更新右侧固定栏
updateFixedRight() {
const {
fixedRightHeaderDom,
dom
} = this.getFixedDom()
if (dom.classList.contains('fixed')) {
const timer = setTimeout(() => {
this.setFixedStyle({
dom: fixedRightHeaderDom,
left: this.fixedRightDom[0].getBoundingClientRect().left + 'px',
width: getComputedStyle(this.fixedRightDom[0]).width,
scrollLeft: fixedRightHeaderDom.scrollWidth
})
clearTimeout(timer)
}, 100)
}
},
async headerDragend() {
await this.updateWidth()
await this.updateFixedRight()
this.setScrollXWidth()
// await this.updateHeaderHeight()
},
setScrollXWidth() {
const timer = setTimeout(() => {
if (!this.parentDom) this.parentDom = document.getElementsByClassName(this.parent)
if (this.parentDom.length === 0) return
const dom = this.parentDom[0].querySelector('.el-table__header')
this.tableWidth = this.parentDom[0].querySelector('.el-table__body-wrapper').getBoundingClientRect().width
this.tableDom[0].style.width = this.tableWidth + 'px'
this.updateHeaderHeight()
this.headerWidth = dom.style.width
clearTimeout(timer)
}, 200)
},
// 更新表格宽度，（拖拽改变宽度时使用）
updateWidth() {
if (!this.parentDom) this.parentDom = document.getElementsByClassName(this.parent)
const bodyWrapperDom = this.parentDom[0].getElementsByClassName('el-table__body-wrapper')[0]
const width = getComputedStyle(bodyWrapperDom).width // 表格宽度
// 给表格设置宽度。
const tableParent = this.tableDom
for (let i = 0; i < tableParent.length; i++) {
tableParent[i].style.width = width
}
},
getFixedDom() {
let fixedRightHeaderDom, fixedRightBox, fixedLeftHeaderDom, fixedLeftBox
const dom = this.tableDom[0]
if (this.fixedLeftDom && this.fixedLeftDom[0]) {
const lefarr = this.fixedLeftDom[0].children
fixedLeftHeaderDom = lefarr[0]
fixedLeftBox = lefarr[1]
}
if (this.fixedRightDom && this.fixedRightDom[0]) {
const rightarr = this.fixedRightDom[0].children
fixedRightHeaderDom = rightarr[0]
fixedRightBox = rightarr[1]
}
return {
fixedRightHeaderDom,
fixedRightBox,
fixedLeftHeaderDom,
fixedLeftBox,
dom
}
},
// 更新表头高度，表头高度有可能改变
updateHeaderHeight() {
this.$nextTick(() => {
this.tableDom = this.parentDom[0].getElementsByClassName('el-table__header-wrapper')
const obj = this.tableDom[0].getBoundingClientRect()
if (obj.height !== this.tablexy.height) {
this.tablexy.height = obj.height
const {
dom
} = this.getFixedDom()
if (dom.classList.contains('fixed')) {
const timer = setTimeout(() => {
this.parentDom[0].getElementsByClassName('el-table__fixed-body-wrapper')[0].style.top = 0
const container = this.containerDom
if (container && container[0]) {
container[0].scrollTop = container[0].scrollTop + 3
}
clearTimeout(timer)
}, 100)
}
}
})
},
// 获取表格属性
getTableXy() {
this.tablexy = this.tableDom[0].getBoundingClientRect()
this.tablexy.height = this.tableDom[0].offsetHeight
return this.tablexy
},
getDom() {
if (!this.parentDom) {
this.parentDom = document.getElementsByClassName(this.parent)
}
},
// 滚动事件
scrollEvent: rafThrottle(async function (e) {
this.getDom()
this.tableDom = this.parentDom[0].getElementsByClassName('el-table__header-wrapper')
if (this.tablexy.top === 0 || !this.tablexy.height || !this.tablexy.top) {
await this.getTableXy()
}
this.fixedRightDom = this.parentDom[0].getElementsByClassName('el-table__fixed-right')
this.fixedLeftDom = this.parentDom[0].getElementsByClassName('el-table__fixed')
const {
height,
top,
left
} = this.tablexy
const scrollTop = e.target.scrollTop
const {
fixedRightHeaderDom,
fixedRightBox,
fixedLeftHeaderDom,
fixedLeftBox,
dom
} = this.getFixedDom()
if (scrollTop >= height / 2 + top - 70) {
// 存在右侧固定表头
if (fixedRightHeaderDom) {
this.setFixedStyle({
dom: fixedRightHeaderDom,
left: this.fixedRightDom[0].getBoundingClientRect().left + 'px',
width: getComputedStyle(this.fixedRightDom[0]).width,
scrollLeft: fixedRightHeaderDom.scrollWidth
})
fixedRightBox.style.top = 0
}
// 左侧固定
if (fixedLeftHeaderDom) {
this.setFixedStyle({
dom: fixedLeftHeaderDom,
left: left + 'px',
width: getComputedStyle(this.fixedLeftDom[0]).width,
scrollLeft: 0
})
fixedLeftBox.style.top = 0
}
dom.classList.add('fixed') // 加一个固定标识
this.updateWidth()
dom.style.position = 'fixed'
dom.style.zIndex = '2000'
dom.style.top = 90 + 'px'
dom.style.overflow = 'hidden'
} else {
this.clearFixedStyle()
}
}),
// 设置固定
setFixedStyle(data) {
const {
dom,
scrollLeft,
width,
left
} = data
dom.style.zIndex = '2000'
dom.style.position = 'fixed'
dom.style.top = '90px'
dom.scrollLeft = scrollLeft
dom.style.width = width
dom.style.overflow = 'hidden'
dom.style.left = left
},
// 清除header固定
clearFixedStyle() {
if (!this.tableDom) return
const {
height,
left
} = this.tablexy
const {
dom,
fixedRightHeaderDom,
fixedRightBox,
fixedLeftHeaderDom,
fixedLeftBox
} = this.getFixedDom()
if (dom.classList.contains('fixed')) {
if (fixedRightHeaderDom) {
fixedRightBox.style.top = height + 'px'
fixedRightHeaderDom.removeAttribute('style')
}
if (fixedLeftHeaderDom) {
fixedLeftHeaderDom.style.zIndex = '0'
fixedLeftHeaderDom.style.position = 'static'
fixedLeftHeaderDom.style.top = 0 + 'px'
fixedLeftHeaderDom.style.left = left + 'px'
fixedLeftBox.style.top = getComputedStyle(dom).height
}
dom.classList.remove('fixed')
dom.style.position = 'static'
dom.style.top = '0'
dom.style.zIndex = '0'
}
}
},
computed: {
__opened() {
// return this.$store.state.app.sidebar.opened
return true
}
},
watch: {
__opened() {
this.$nextTick(() => {
this.setScrollXWidth()
})
}
},
data() {
return {
tablexy: {}, // 表格的左边宽度信息
fixedRightDom: null, // 右侧
fixedLeftDom: null, // 左侧栏固定
scrollDom: null, // 滚动的dom
parentDom: null, // 表格的父元素dom
tableWidth: 0,
timerList: [],
tableDom: null,
containerDom: null
}
}
}
在引入el-table地方
import sticky from '@/utils/table-sticky.js'
mixins: [sticky],
