text: import { createStore , combineReducers , applyMiddleware } from 'redux'
  import * as reducer from '../reducer/index'
  import thunk from 'redux-thunk'
  
  //创建一个  Redux store 来存放应用中所有的state,应用中有且只有一个store
  
  const Store = createStore(
      combineReducers(reducer),
      applyMiddleware(thunk),
  );
  export default Store;