操作必须是纯对象。使用自定义中间件进行异步操作，但我使用的是redux-thunk

// 安装redux-thunk并配置中间件
import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import rootReducer from './reducers';

const store = createStore(rootReducer, applyMiddleware(thunk));

// 定义一个异步的action创建函数
export const fetchData = () => {
  return (dispatch, getState) => {
    dispatch({ type: 'FETCH_DATA_REQUEST' });

    // 异步操作，例如发送网络请求
    fetch('https://api.example.com/data')
      .then(response => response.json())
      .then(data => {
        dispatch({ type: 'FETCH_DATA_SUCCESS', payload: data });
      })
      .catch(error => {
        dispatch({ type: 'FETCH_DATA_FAILURE', payload: error });
      });
  };
};

// 在组件中使用异步action
import { connect } from 'react-redux';
import { fetchData } from './actions';

class MyComponent extends React.Component {
  componentDidMount() {
    this.props.fetchData();
  }

  render() {
    // 渲染组件
  }
}

export default connect(null, { fetchData })(MyComponent);