使用vue3自定义指令实现Tooltip

效果预览：

 

实现代码：

directive.js

import { nextTick } from "vue"

function elFover(e) {

	// e.el.classList.add('hover')

	let res = e.el.getBoundingClientRect()
	// console.log(res)

	let dom_tooltip = document.querySelector('.c-tooltip')
	
	if(dom_tooltip) {
		dom_tooltip.style.display = 'block'
		dom_tooltip.querySelector('.ivu-tooltip-inner').innerText = e.val
	
	} else {
		let _div = document.createElement('div')
		_div.innerHTML = `

		

			

			
${e.val}
		
	
`
		document.body.appendChild(_div)

		
	}

	nextTick(() => {
		!dom_tooltip && (dom_tooltip = document.querySelector('.c-tooltip'))
		let _res = dom_tooltip.getBoundingClientRect()

		if(res.top < _res.height) {
			dom_tooltip.style.top = res.bottom +'px'
			dom_tooltip.setAttribute('x-placement', 'bottom')
		} else {
			dom_tooltip.style.top = (res.top - _res.height) +'px'
			dom_tooltip.setAttribute('x-placement', 'top')
		}

		if(res.left < (_res.width - res.width)/2) {
			dom_tooltip.style.left = 0 +'px'
		} else if(window.innerWidth - res.right < (_res.width - res.width)/2) {
			dom_tooltip.style.left = (window.innerWidth - _res.width) +'px'
		} else {
			dom_tooltip.style.left = (res.left + (res.width - _res.width)/2) +'px'
		}

		
	})
	
}

function elLeave() {
	let dom_tooltip = document.querySelector('.c-tooltip')
	
	if(dom_tooltip) {
		dom_tooltip.style.display = 'none'
	}
}

let fb = undefined

export const vFocus = {
	mounted: (el, binding) => {
		fb = elFover.bind(this, {
			el: el,
			val: binding.value
		})
		el.addEventListener('mouseenter', fb)
		el.addEventListener('mouseleave', elLeave)
	},
	// 绑定元素的父组件卸载前调用
  beforeUnmount(el, binding, vnode, prevVnode) {
		el.removeEventListener('mouseenter', fb)
		el.removeEventListener('mouseleave', elLeave)
	},
}

main.ts

import { vFocus } from '@/utils/directive.js'
import { createApp } from 'vue'

const app = createApp(App)
app.directive('focus', vFocus)

组件里使用