第四章 react-redux，@reduxjs/toolkit依赖，学习

redux系列文章目录

第一章 简单学习redux,单个reducer

第二章 简单学习redux,多个reducer

第三章 redux和react-redux，@reduxjs/toolkit依赖结合使用

第五章 两张图告诉你redux常使用的api有哪些

前言

本章将使用react-redux，@reduxjs/toolkit依赖创建一个简单cout计数页面

准备工作

准备一个react框架的环境

npx create-react-app  react-redux-template

下载依赖

npm i react-redux @reduxjs/toolkit

启动命令

npm start

准备目录文件，
页面：src/pages/count/index.js
redux的存放：src/redux/store.js和src/redux/counterReducer.js

详情代码

store.js

import { configureStore } from "@reduxjs/toolkit";
import countReducer from "./countReducer";
const store = configureStore({
  reducer: {
    counter: countReducer,
  },
})

export default store;

counterReducer.js

import { createSlice } from "@reduxjs/toolkit";

const countSlice = createSlice({
  name: "counter",
  //这里initialState一定到放对象object，不然报错
  initialState: {value: 0},
  reducers: {
    increment: (state) => {
        state.value +=1
    },
    decrement: (state) => {
        state.value-=1
    }
  },
}
)
export const {increment, decrement} = countSlice.actions
export default countSlice.reducer

count/index.js

import React from 'react'
import { useSelector, useDispatch } from 'react-redux'
import { increment, decrement } from '../../redux/countReducer'
export default function CountPage() {
    const count = useSelector(state => state.counter.value)
    const dispatch = useDispatch()

    return (
        <div>
            <br />
            <br />count:{count}
            <br />
            <button onClick={() => {
                dispatch(increment())
            }}>加+1</button>
            &nbsp;
            <button onClick={() => { dispatch(decrement()) }}>减-1</button>

        </div>
    )
}

src/index.js

import React from 'react';
import ReactDOM from 'react-dom/client';
import './index.css';
// import App from './App';
import CountPage from './pages/count';
import reportWebVitals from './reportWebVitals';
import { Provider } from 'react-redux';
import store from './redux/store';
const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(
  <React.StrictMode>
    <Provider store={store}>
    <CountPage />
    </Provider>
  </React.StrictMode>
);

reportWebVitals();

提示：<Provider>很重要，引入store,这样整个应用都可以使用store相关hooks拿取数据

效果