无法使用React-redux中的connect访问存储

import { Provider } from 'react-redux';
import store from './store'; // 导入Redux store

ReactDOM.render(
  <Provider store={store}>
    <App />
  </Provider>,
  document.getElementById('root')
);

import { connect } from 'react-redux';

class MyComponent extends React.Component {
  // 组件的代码...
}

const mapStateToProps = (state) => {
  return {
    // 将存储中的状态映射到组件的props中
    myState: state.myState
  };
};

export default connect(mapStateToProps)(MyComponent);

// 定义action
const updateMyState = (data) => {
  return {
    type: 'UPDATE_MY_STATE',
    payload: data
  };
};

// 定义reducer
const myReducer = (state = initialState, action) => {
  switch (action.type) {
    case 'UPDATE_MY_STATE':
      return {
        ...state,
        myState: action.payload
      };
    default:
      return state;
  }
};

// 在store中应用reducer
const store = createStore(myReducer);