React+Redux搭建项目

• 原理

  react数据改变是通过state来处理的，而添加redux是为了通过一个store统一管理state数据变化，单向数据流:
  action->reducer->store-> state

• 原料

  • redux

    用于创建store，创建reducer, 管理日志打印，用到方法(createStore, combineReducers, createLogger)

  • react-redux: Provider

    用于将Store绑定在项目上

  • redux-thunk

    中间件，用于异步处理

  • redux-logger

    用与打印日志

• 项目结构

src
|-- store
|-- reducers
|-- middleware
|-- components
|-- container
|-- common

• 项目搭建

1. 创建单个reducer,在reducers文件夹下添加count.js,并新增如下代码

   const initialState = {
       num: 0
   }
   export default (state = initialState, action) => {
       switch (aciton.type) {
           case "ADD": /**可建立一个actionType.js用常量定义aciton*/
           retrun {
               num: state.num + 1
           }
       }
   }
   

2. 将单个reducer并合在一起，如刚刚新添加的（count.js）,在reducers文件夹下添加index.js

   import { combineReducers } from "redux";
   import count from "./count"
   
   export default combineReducers({
       count,
   })
   

3. 创建store，在store文件夹下添加configureStore.js

   import { createStore，applyMiddleware } from "redux"
   import thunk from "redux-thunk"
   import { createLogger } from "redux-logger"
   import rootReducer from "../reducers"
   
   export default function configureStore(preloadedState) {
       const store = createStore(
           rootReducer,
           preloadedState, /**初始state，可省略*/
           applyMiddleware(thunk, createLogger({
               duration: 1000,
               predicate: ture, /**判断日志打印条件如：生产环境*/
               stateTransfomer: (state) => {
                   var result = {}
                   Object.keys(state).filter( key => {
                       if (state[key].toJS) {
                           result[key] = state[key].toJS()
                       } else {
                           result[key] = state[key]
                       }
                   })
                   return reuslt
               }
           })
           
       )
   }
   

4. 项目中添加store，用于管理state,在根目录的index.js中改写

   import React from 'react';
   import ReactDOM from 'react-dom';
   import './index.css';
   import App from './App';
   import * as serviceWorker from './serviceWorker';
   import { Provider } from "react-redux"
   import configureStore  from "./store/configureStore"
   
   const stores = configureStore({})
   
   ReactDOM.render(
       
           
       ,
   document.getElementById('root'));
   
   // If you want your app to work offline and load faster, you can change
   // unregister() to register() below. Note this comes with some pitfalls.
   // Learn more about service workers: http://bit.ly/CRA-PWA
   serviceWorker.unregister();
   
   

5. 在页面中通过action更改数据 connect是将store中(state, dispatch)传入页面,动态渲染页面

   import React, { Component } from 'react';
   import logo from './logo.svg';
   import './App.css';
   import { connect } from "react-redux"
   
   class App extends Component {
   
     constructor(props) {
       super(props)
       console.log("prop", props)
     }
     render() {
       return (
         
   
           
   {this.props.num}
           
   +++++
         
       );
     }
   }
   
   function mapStateToProps(state) {
     const { count } = state
     console.log("sss", count)
     return {
       num: count.num
     }
   }
   function mapDispatchToProps(dispatch) {
     return {
       add: () => dispatch({
         type: "ADD"
       })
     }
   }
   
   export default connect(mapStateToProps, mapDispatchToProps)(App);