需求:鼠標移入/移出div范圍時,樣式發生改變
import React,{useState,useEffect} from 'react'; import ReactDOM from 'react-dom'; import './index.css'; function ChangeStyle(){ const [isHover,setHover]=useState(false); return( <div id="div1" className={isHover ? 'hover' : ''} onMouseOver={()=>setHover(true)} onMouseOut={()=>setHover(false)} >鼠標移入改變樣式,鼠標移出恢復。</div> ) } ReactDOM.render( <ChangeStyle/>, document.getElementById('root') )