说明
1）所有变量名字要规范，尽量触发对象的简写形式
2）reducers文件夹中，编写index.js专门用于汇总并暴露所有的reducer
项目结构
代码示例
index.js
import React from 'react'
import ReactDOM from 'react-dom'
import App from './App.jsx'
import store from './redux/store'//为provider服务
import {Provider} from 'react-redux'
ReactDOM.render(
//此处需要用provider包裹App，目的是让App所有的后代容器组件都能够接收到store
<Provider store= {store}>
<App/>
</Provider>,
document.getElementById('root')
)
App.jsx
import React, { Component } from 'react'
import Count from './containers/Count'//引入的是Count的容器组件
import Person from './containers/Person'//引入的是Person的容器组件
export default class App extends Component {
render() {
return (
<div>
<Count/>
<hr/>
<Person/>
</div>
)
}
}
redux-store.js
/*
该文件专门用于暴露一个store对象，整个应用只有一个store对象
*/
//引入createStore，专门用于创建redux中最为核心的store对象,applyMiddleware用于支持
//异步action的中间件
//combineReducers用于合并多个reducer
import {createStore,applyMiddleware} from 'redux'
//引入汇总之后的reducers
import reducer from './reducers'
//引入redux-thunk，用于支持异步action
import thunk from 'redux-thunk'
//引入redux-devtools-extension
import {composeWithDevTools} from 'redux-devtools-extension'
export default createStore(reducer, composeWithDevTools(applyMiddleware(thunk)))redux-constant.js
/*
该文件是用于定义action对象中的type类型的常量值
目的只有一个：防止程序员在编码的同时单次写错
*/
export const INCREMENT = 'increment'
export const DECREMENT = 'decrement'
export const ADD_PERSON = 'add_person'redux-reducers-index.js
/*
该文件用于汇总会有的reducer为一个总的reducer
*/
//引入combineReducers，用于汇总多个reducer
import {combineReducers} from 'redux'
//引入为Count组件服务的reducer
import count from './count'
//引入为Person组件服务的reducer
import persons from './person'
//汇总所有的reducer变为一个总的reducers
export default combineReducers({
count,
persons
})
redux-reducers-count.js
/*
1.该文件用于创建一个为count组件服务的reducer，reducer的本质就是一个函数
2.reducer函数会接到两个参数，分别是之前的state(状态)和action(动作对象)
*/
import { INCREMENT, DECREMENT } from "../constant";
const initState = 0
export default function countReducer(preState=initState, action) {
console.log(preState, action);
//从action对象中获取type, data
const {type, data} = action
//根据type类型决定如何加工
switch (type) {
case INCREMENT:// 如果是加
return preState + data
case DECREMENT:// 如果是减
return preState - data
default:
return preState
}
}redux-reducers-person.js
import { ADD_PERSON } from "../constant"
//初始化人的列表
const initState = [{id:'001',name:'tom', age:18}]
export default function personReducer(preState=initState, action) {
const {type,data} = action
switch(type) {
case ADD_PERSON:
return [data, ...preState]// 若是添加一个人
default:
return preState
}
}redux-actions-count.js
/*
该文件专门为count组件生成action对象
*/
import { INCREMENT, DECREMENT } from "../constant"
//完整写法
// function createIncrementAction(data) {
// return {type:'increment', data }
// }
//简写形式
//同步action，就是值action的返回值是Object类型的一般对象
export const increment = data =>( {type:INCREMENT, data })
//完整写法
// function createDecrementAction(data) {
// return {type:'decrement', data}
// }
export const decrement = data =>( {type: DECREMENT, data })
//异步action，就是值action的返回值是函数，异步action一般都会调用同步action
//异步action不是必须要用的
export const incrementAsync = (data, time) =>{
return (dispatch) => {
setTimeout(() => {
dispatch(increment(data))
},time)
}
}redux-actions-person.js
import {ADD_PERSON} from '../constant'
//创建增加一个人的action对象
export const addPerson = personObj => ({type:ADD_PERSON, data:personObj})container-count-index.jsx
//引入CountUI组件
// import CountUI from '../../compoents/Count'
import React, { Component } from 'react'
//引入connect用于连接UI组件和redux
import {connect} from 'react-redux'
//引入action
import {
increment,
decrement,
incrementAsync
} from '../../redux/actions/count'
//定义UI组件
class Count extends Component {
state = {carName:'奔驰c63'}// 把状态交给reducer之后组件也可以有自己独用的状态
increment = () => {
const {value} = this.selectNum
this.props.increment(value*1)
}
decrement = () => {
const {value} = this.selectNum
this.props.decrement(value*1)
}
incrementOdd = () => {
const {value} = this.selectNum
if(this.props.count % 2 !== 0) {
this.props.increment(value*1)
}
}
incrementWait = () => {
const {value} = this.selectNum
this.props.incrementAsync(value*1,400)
}
render() {
console.log('UI组件接收到的props是：',this.props);
return (
<div>
<h2>我是Count组件,下方组件总人数是：{this.props.personCount}</h2>
<h3>当前求和为：{this.props.count}</h3>
<select ref={c => {this.selectNum = c}}>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<button onClick= {this.increment}>+</button>
<button onClick= {this.decrement}>-</button>
<button onClick= {this.incrementOdd}>当前求和为奇数再加</button>
<button onClick= {this.incrementWait}>等一等再加</button>
</div>
)
}
}
//使用connect()()创建并暴露一个Count容器组件
export default connect(
state => ( {
count:state.count,
personCount:state.persons.length
}),
//mapDispatchToProps的一般写法
// dispatch => ({
// jia:number => dispatch(createIncrementAction(number)),
// jian:number => dispatch(createDecrementAction(number)),
// jiaAsync:(number,time) =>dispatch(createIncrementAsyncAction(number,time))
// })
//mapDispatchToProps的简写,dispatch由react-redux来完成,程序员工作中用这种方法
{
increment,
decrement,
incrementAsync
}
)(Count)container-person-index.jsx
import React, { Component } from 'react'
import {nanoid} from 'nanoid'
import {connect} from 'react-redux'
import {addPerson} from '../../redux/actions/person'
class Person extends Component {
addPerson = () => {
const name = this.nameNode.value
const age = this.ageNode.value
const personObj = {id:nanoid(), name, age}
this.props.addPerson(personObj)
this.nameNode.value = ''
this.ageNode.value = ''
}
render() {
return (
<div>
<h2>我是person组件,上方组件求和为{this.props.count}</h2>
<input ref={c => this.nameNode = c} type="text" placeholder="请输入姓名"/>
<input ref={c => this.ageNode = c} type="text" placeholder="请输入年龄"/>
<button onClick= {this.addPerson}>添加</button>
<ul>
{
this.props.persons.map((p) => {
return <li key={p.id}>{p.name}--{p.age}</li>
})
}
</ul>
</div>
)
}
}
export default connect(
state => ({
persons:state.persons,
count:state.count
}),// 映射状态
{addPerson}//映射操作状态的方法
)(Person)