父组件拿到子组件的值：使用forwardRef

import {  forwardRef,useRef } from 'react';

const Input = forwardRef((props,ref)=>{
  return <input type="text" ref={ref} />
})

const App = () => {
 const inputRef = useRef(null);
 const showRef = () => {
   console.log(inputRef.current.value);
 }
  return (
    <div className="home">
     <Input ref={inputRef} />
     <button onClick={showRef}>拿到子组件的值</button>
    </div>
  )
}

export default App