react-redux with thunk - getState不是一个函数

import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import { Provider, useDispatch } from 'react-redux';
import { useSelector } from 'react-redux';

// 定义action类型和action创建函数
const FETCH_DATA = 'FETCH_DATA';
const fetchData = () => {
  return (dispatch, getState) => {
    // 在异步操作中使用getState函数
    const currentState = getState();
    console.log(currentState);

    // 异步操作逻辑
    // ...

    dispatch({ type: FETCH_DATA, payload: data });
  };
};

// 定义reducer
const reducer = (state = initialState, action) => {
  switch (action.type) {
    case FETCH_DATA:
      return { ...state, data: action.payload };
    default:
      return state;
  }
};

// 创建store
const store = createStore(reducer, applyMiddleware(thunk));

// 在组件中使用getState函数
const MyComponent = () => {
  const dispatch = useDispatch();
  const data = useSelector((state) => state.data);

  const fetchDataHandler = () => {
    dispatch(fetchData());
  };

  return (
    <div>
      <button onClick={fetchDataHandler}>Fetch Data</button>
      <p>{data}</p>
    </div>
  );
};

// 渲染应用
ReactDOM.render(
  <Provider store={store}>
    <MyComponent />
  </Provider>,
  document.getElementById('root')
);