TypeError：無法解構“productDetails”的屬性“product”，因為它未定義

Question

**ProductDetailsScreen.js >>> 這是我的代碼，我從 Redux 商店獲得了產品列表，但是在初始化產品詳細信息時遇到了問題。 **

export default function ProductDetilsScreen(props) {
  const dispatch = useDispatch();
  const productId = props.match.params.id;
  const productDetails = useSelector((state) => state.productDetails);
  const { loading, error, product } = productDetails;

  useEffect(() => {
    dispatch(detailsProduct(productId));
  }, [dispatch, productId]);

**productActions.js >> 這是我的代碼，我從 Redux 商店獲得產品列表，但在初始化產品詳細信息時遇到問題。 **

export const detailsProduct = (productId) => async (dispatch) => {
  dispatch({
    type: PRODUCT_DETAILS_REUEST,
    payload: productId,
  });
  try {
    const { data } = await Axios.get(`/api/products/${productId}`);
    dispatch({
      type: PRODUCT_DETAILS_SUCCESS,
      payload: data,
    });
  } catch (error) {
    dispatch({
      type: PRODUCT_DETAILS_FAIL,
      payload:
        error.response && error.response.data.message
          ? error.response.data.message
          : error.message,
    });
  }
};

**productReducer.js >>> 這是我的代碼，我從 Redux 商店獲得了產品列表，但是在初始化產品詳細信息時遇到了問題。 **

export const productDetailsReducer = (
  state = { product: {}, loading: true },
  action
) => {
  switch (action.type) {
    case PRODUCT_DETAILS_REUEST:
      return { loading: true };
    case PRODUCT_DETAILS_SUCCESS:
      return { loading: false, product: action.payload };
    case PRODUCT_DETAILS_FAIL:
      return { loading: false, error: action.payload };
    default:
      return state;
  }
};

**Store.js >>> 這是我的代碼，我從 Redux 商店獲得產品列表，但在初始化產品詳細信息時遇到問題。 **

import { applyMiddleware, combineReducers, compose, createStore } from "redux";
import thunk from "redux-thunk";
import { productDetailsReducer, productListReducer } from "./productReducers";

const initialState = {};

const reducer = combineReducers({
  productList: productListReducer,
  productDetils: productDetailsReducer,
});
const composeEnhancer = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
const store = createStore(
  reducer,
  initialState,
  composeEnhancer(applyMiddleware(thunk))
);

export default store;

Answer 1

似乎這里有一個錯字，可能會導致問題。

// productDetils in Store.js file
const reducer = combineReducers({
  productList: productListReducer,
  productDetils: productDetailsReducer,
});

// productDetails in ProductDetailsScreen.js file
const productDetails = useSelector((state) => state.productDetails);
const { loading, error, product } = productDetails;

嘗試糾正這個粗心的錯誤。

除此之外，似乎沒有什么異常。 您對productDetails的初始 state 形式為state = { product: {}, loading: true }似乎是正確的。