import React, {useRef, useState} from 'react';

export default function Demo(props) {
    const myRef=useRef()
    const [data,SetData]=useState()
    function changeRef() {
        SetData(myRef.current.value)
    }
    return (
        <>
            <input ref={myRef} onChange={changeRef}/>
            <hr/>
            <h3>展示结果：{data}</h3>
        </>
    );
}