TypeError: Object(…) is not a function React.js

Question

[![在此處輸入圖片描述][1]][1] 文件名：productScreen.js

錯誤：第 6 行 - TypeError: Object(...) is not a function

路徑：src/Screens/ProductScreen.js

代碼如下：

  3 | import { Link } from "react-router-dom";
  4 | import { detailsProduct } from "../actions/productActions";
  5 | function ProductScreen(props){
  >6|     const productDetails= useSelector(state => state.productDetails);
  7 |     const {product , loading , error} = productDetails;
  8 |     const dispatch = useDispatch();
  9 |     useEffect(()=>{
  10|          dispatch(detailsProduct(props.match.params.id));
  11|         return () => {
  12|        };
  13|    } , [])

文件名：store.js

路徑：src/store.js

代碼如下：

    1|const initialState = {}
    2|const reducer = combineReducers({
    3|productList: productListReducer,
    4|productDetails: productDetailsReducer
    5| })
    6|const composeEnhancer = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
    7|const store = createStore(reducer , initialState , composeEnhancer(applyMiddleware(thunk)));
    8|export default store;

文件名：index.js

路徑：src/index.js

代碼如下：

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

所有的進口都是正確的

Answer 1

您似乎缺少useSelector導入語句。

添加import { useSelector } from "react-redux"; 在您的ProductScreen.js文件中。