react v-18父组件调用子组件的方法和数据

版本

"react": "^18.1.0",
"react-dom": "^18.1.0",

父组件

import React, { useState, useRef, memo, useEffect } from "react";
import { useTranslation } from "react-i18next";
import { Card } from "antd";

import Childdren from './child/child';
function Dashboard() {
  let childRef:any = useRef(null);
  const handleClick = () => {
     console.log('子组件：', childRef.current)  //打印：{num: 999, add: ƒ}
    childRef.current.add() //调用
  }
  return (
        <Card style={
  { minHeight: "calc(100vh - 64px)" }}>
            <Childdren ref={childRef} title={'我是父组件的数据'} num={123} fun={() => alert('传递了一个函数')} />
            
            <button onClick={handleClick}>父组件调子组件方法</button>
        </Card>
  );
}

export default Dashboard;

子组件 (通过useImperativeHandle() 抛出）

// props （类组件则使用this.props）
import React, { useImperativeHandle } from "react";
const Childdren = React.forwardRef((props:any, ref) => {
  useImperativeHandle(
    ref,
    () => ({ add,num }) //父组件通过ref获取值，要在这里抛出
  );
  const num = 999;
  const add = () => {
    console.log('我是子组件方法')
  };
  return (
    <div>
      <h1>父传子：{props.title}</h1>
      <button >这是子组件</button>
      
    </div>
  );
});
export default Childdren;