App.js的代码
06是函数组件
07是类组件
javascript
import React, { useEffect, useRef } from 'react';
import LearnFunction06 from './LearnFunction06'; // 函数组件和类组件的ref使用方式
import LearnFunction07 from './LearnFunction07'; // 函数组件和类组件的ref使用方式
export default function BoxReact() {
const learnRef = useRef(null)
const classRef = useRef(null)
useEffect(() => {
console.log(learnRef.current);
console.log(classRef.current);
}, [])
return (
<div>
<LearnFunction06 ref={learnRef}></LearnFunction06>
<LearnFunction07 ref={classRef}></LearnFunction07>
</div>
)
}
06的代码
javascript
import React, { forwardRef } from 'react'
export default forwardRef(function LearnFunction06(props, ref) {
return (
<div ref={ref}> LearnFunction06</div>
)
})
正常函数组件是没有ref的,需要通过forwardRef来修饰组件才能产生ref
07的代码
javascript
import React, { Component } from 'react'
export default class LearnFunction07 extends Component {
render() {
return (
<div>LearnFunction07</div>
)
}
}
效果图
这样都可以拿到ref啦