import { createStore, applyMiddleware, compose} from 'redux';     // 从redux中调用 createStore 方法

import reducer from './reducer';

import thunk from 'redux-thunk';

const composeEnhancers =

  window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ ?

  window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({}) : compose;

const enhancer = composeEnhancers(

  applyMiddleware(thunk)

);

const store = createStore(reducer, enhancer);

export default store;

解决了