react怎么请求数据异步

npm i redux-thunk --save
npm i axiOS --save

import {createStore,applyMiddleware} from 'redux'   //引入applyMiddleware
import reducers from './reducers'  //总的reducer
import thunk from 'redux-thunk'   //引入thunk 
var store = createStore(reducer,applyMiddleware(thunk));  //使用中间件
export default store;

import axios from 'axios'
export default {
    getData(){
        return (dispatch)=>{   // 引入中间件redux-thunk后，就可以延迟发出动作
                axios.get('Http://www.xmyxapp.com/api/tab/1?start=0').then((res)=>{
                    console.log(res)
                    dispatch({
                        type:'GETDATA',
                        list:res.data.data.items.list
                    })
                })
        }
    }
}

var initState  ={
    list:[]
}
export const listReducer = (state = initState, action) => {
    var newState ={...state};
    switch (action.type) {
        case 'GETDATA':
            newState.list = action.list  // 这个action.list就是该模块actionCreator里传过来的值
            return newState;
        default:
            return state
    }
}

import {combineReducers} from 'redux'
import {listReducer} from '../components/list/reducer'
 var reducer = combineReducers({
     list:listReducer
 })
 export default reducer;

import React, { Component } from 'react'
import {connect} from 'react-redux'
import actionCreator from './actionCreator';
 class List extends Component {
  componentDidMount(){
      this.props.getData();   // 调用异步方法获取数据
  }
  render() {
      console.log(this.props);
    return (
      <div>
        <ul>
            {
                this.props.list.list.map((item)=>{
                    return item.title?<li key={item.id}>{item.title}</li>:""
                })
            }
        </ul>
      </div>
    )
  }
}
export default connect((state)=>state,actionCreator)(List);