1 添加依赖@reduxjs/toolkit，react-redux
2 全局组件app 添加store.要引入store import store from './store/store'
3 创建store ,引入reducer
4 slice.js reducer写在这里面
5
6 add是方法，action确定哪个切片下的哪个方法，state.n是所在切片初始值的key值表示
import { useDispatch, useSelector } from 'react-redux'
//count是countSlice切片里的name对应的count代表使用的是countSlice切片
const { count,emp } = useSelector(state => state)
