react memo useSelector

当props参数变化时组件才发生更改
const ImplicitSnowy = React.memo(props => (

implicit memoized component

));

useSelector()
const result : any = useSelector(selector : Function, equalityFn? : Function)
主要作用：
从redux的store对象中提取数据(state)。
export const CounterComponent = () => {
const counter = useSelector(state => state.counter)
return

{counter}

}

useDispatch()
const dispatch = useDispatch()
返回Redux store中对dispatch函数的引用。你可以根据需要使用它。

import React from 'react'
import { useDispatch } from 'react-redux'

export const CounterComponent = ({ value }) => {
const dispatch = useDispatch()

return (

{value}
<button onClick={() => dispatch({ type: 'increment-counter' })}>
Increment counter

)
}