reac中useCallback使用
作者:互联网
import React,{useState,useCallback} from "react"
const Son = React.memo( ({a,c}) =>{
console.log('son 重新渲染');
return (
<div>
a:{a}
<button onClick={c}>点击</button>
</div>
)
})
export default function useCallBack(){
const [a, setA] = useState(0);
const [b, setB] = useState(0);
// const memoHandClick = () => console.log("click");
const memoHandClick =useCallback(() =>{console.log("click")},[]) //避免的重新生成回调函数 保证了Son组件的重新渲染
return(
<div>
{console.log('UseCallBack 渲染')}
<Son a={a} c={memoHandClick} />
<button onClick={() =>{setA(a +1 )}}>改变A</button>
<button onClick={() =>{setB(b +1 )}}>改变B</button>
<button onClick={memoHandClick}>click</button>
</div>
)
}
效果:
标签:const,log,reac,useState,使用,console,useCallback,click 来源: https://www.cnblogs.com/malong1992/p/15361364.html