npm  install  redux-persist

目录：（分模块）

之前未加入持久化的代码：

import { legacy_createStore as createStore } from 'redux'
import { combineReducers } from "redux";
import countReducer from './modules/countReducer'

const reducer = combineReducers({
    countReducer
})

const store = createStore(reducer)

export default store

加入持久化后：

import { legacy_createStore as createStore, combineReducers, applyMiddleware } from 'redux'
import countReducer from './modules/countReducer'

import { persistReducer, persistStore } from 'redux-persist'
import storage from 'redux-persist/lib/storage'


const reducer: any = combineReducers({
    countReducer
})

const persist_reducer = persistReducer({ key: 'demo', storage }, reducer)

const store = createStore(persist_reducer)
const persist_store = persistStore(store)
const clear_persist_store = () => {
    localStorage.removeItem(`persist:demo`)
}

export {
    store,
    persist_store,
    clear_persist_store
}

index.tsx:

浏览器 localStorage: