当我将我的app组件封装在提供程序中时，整个网页都为空，控制台中出现了一些错误。

Question

//我的store.js

import {createStore, combineReducers, applyMiddleware} from "redux";
import thunk from "redux-thunk";
import {composeWithDevTools} from "redux-devtools-extension";
import {
    //productsDetailReducer,
    productsReducer,
} from "./reducers/productReducer";
import {userReducer} from "./reducers/useReducer";

const reducer = combineReducers({
    products: productsReducer,
    //productDetails: productsDetailReducer,
    user: userReducer,
});

const initialState = null;

const middleware = [thunk];

const store = createStore(
    reducer,
    initialState,
    composeWithDevTools(applyMiddleware(...middleware))
);

export default store;

//ProductReducer.js

import {
    ALL_PRODUCT_FAIL,
    ALL_PRODUCT_REQUEST,
    ALL_PRODUCT_SUCCESS,
    CLEAR_ERRORS,
} from "../constants/productConstants";
export const productsReducer = (state = {products: []}, action) => {
    switch (action.type) {
        case ALL_PRODUCT_REQUEST:
            return {
                loading: true,
                product: [],
            };
        case ALL_PRODUCT_SUCCESS:
            return {
                loading: false,
                product: action.payload.products,
                productsCount: action.payload.productsCount,
            };
        case ALL_PRODUCT_FAIL:
            return {
                loading: false,
                product: action.payload,
            };
        case CLEAR_ERRORS:
            return {
                ...state,
                error: null,
            };
        default:
            return state;
    }
};

//index.js

import React from "react";
import ReactDOM from "react-dom";
import App from "./App";
//import {BrowserRouter} from "react-router-dom";
import {Provider} from "react-redux";
import store from "./store";
ReactDOM.render(
    <Provider store={store}>
        <App />
    </Provider>,
    document.getElementById("root")
);

//错误

未定义错误:键"user“的切片还原器在初始化过程中返回未定义的值。如果传递给还原器的状态未定义，则必须显式返回初始状态。初始状态可能不是未定义的。如果不想为这个还原器设置一个值，可以使用null而不是未定义的。

Answer 1

只是犯了同样的错误。我花了一个小时才意识到我还没有在我的减速机里设置默认的箱子。您没有提供userReducer代码，但我认为问题在于默认情况。尝试返回默认情况下的状态。会起作用的