React-Redux中actions

一、同步actions

1.概念

说明：在reducers的同步修改方法中添加action对象参数，在调用actionCreater的时候传递参数，数会被传递到action对象payload属性上。

2.reducers对象

说明：声明函数同时接受参数

const counterStore=createSlice({
    name:"counter",
    // 初始化状态
    initialState:{
        count:0
    },
    // 修改状态的方法 同步方法
    reducers:{
        addToNum(state,action){
            state.count+=action.payload
        }
    }
})
// 解构actionCreater函数
const {addToNum}= counterStore.actions
// 获取reducer
const reducer=counterStore.reducer

// 按需导出actionCreator
export {addToNum}

// 以默认导出的方式导出reducer
export default reducer

3.app.js

说明：导入函数进行调用。

import { useDispatch, useSelector } from "react-redux";
import {addToNum} from "./store/modules/counterStore"
function App() {
  const {count}=useSelector(state=>state.counter)
  const dispatch=useDispatch()
  return (
    <div className="App">
  <button onClick={()=>dispatch(addToNum(10))}>add To 10</button>
    </div>
  );
}

export default App;

二、异步actions

1.channelStore.js

import {createSlice} from "@reduxjs/toolkit"
import axios from 'axios'
// 1.创建store写法保持不见，配置好同步修改状态的方法
const channelStore= createSlice({
    name:'channel',
    initialState:{
        channelList:[]
    },
    reducers:{
        setChannels(state,action){
            state.channelList=action.payload
        }
    }
})

// 异步请求
const {setChannels}=channelStore.actions

const fetchChannelList=()=>{
    return async(dispatch)=>{
       await axios.get('https://st2msh.laf.run/react_get_list').then(res=>{
        dispatch(setChannels(res.data))
       }).catch(err=>{
        console.log(err);
       })
    }
}

export {fetchChannelList}
const reducer=channelStore.reducer



export default reducer

2. index.js

import { configureStore} from "@reduxjs/toolkit"
// 导入子模块reducer
import counterReducer from "./modules/counterStore"
import channelReducer from "./modules/channelStore"


const store=configureStore({
    reducer:{
        counter:counterReducer,
        channel:channelReducer
    }
})

export default store

3.app.js

import { useDispatch, useSelector } from "react-redux";
import {inscrement,decrement,addToNum} from "./store/modules/counterStore"
import {fetchChannelList} from "./store/modules/channelStore"
import { useEffect } from "react";
function App() {
  const {count}=useSelector(state=>state.counter)
  const {channelList}=useSelector(state=>state.channel)
  const dispatch=useDispatch()

  useEffect(()=>{
    dispatch(fetchChannelList())
  },[dispatch])
  return (
    <div className="App">
            {count}
            <button onClick={()=>dispatch(inscrement())}>+</button>
            <button onClick={()=>dispatch(decrement())}>-</button>
  <button onClick={()=>dispatch(addToNum(10))}>add To 10</button>
   <ul>
    {channelList.map(item=><li key={item.id}>{item.name}</li>)}
   </ul>
   
    </div>
  );
}

export default App;