小编Ebr*_*mid的帖子

在我的应用程序中，我使用的是 React Hooks/Context API。现在，每当我的 Provider 组件挂载时，我都需要将从 localStorage 获取的数据分配给 initialState.carts / state.carts。如果 useEffect 支持返回对象，这是可能的。但是不能在 useEffect 中返回对象！

现在我该如何解决这个问题？

代码如下，

const initialState = {
  books: books,
  carts: []
};

export const Context = createContext(initialState);

export const Provider = ({ children }) => {
  const [state, dispatch] = useReducer(reducer, initialState);

  useEffect(() => {
    if (localStorage.getItem("carts") !== null) {
      const fetchedCarts = JSON.parse(localStorage.getItem("carts"));
      //Here I want to assign 'fetchedCarts' array items in 'state.carts' or 'initialState.carts'
    }
  });

如果用户未注册，API 会抛出 401。但即使有错误，extraReducers 也会执行已完成的情况。500 和其他错误也会发生这种情况。

额外减速器

  extraReducers: (builder) => {
    builder
      .addCase(login.pending, function (state) {
        console.log("pending");
        state.isLoading = true;
      })
      .addCase(login.fulfilled, (state, action) => {
        console.log("fullfield");
        state.isLoading = false;
        state.user = action.payload;
        state.isAuthenticated = true;
      })
      .addCase(login.rejected, (state, action) => {
        console.log("rejected");
        console.log(action.payload);
        state.isLoading = false;
        state.error = true;
        state.message = action.payload;
        state.user = null;
      });
  }

asyncThunk登录方法

export const login = createAsyncThunk("auth/login", async (user, thunkAPI) => {
  try {
    let user = await authService.login(user);
    return user;
  } catch (error) …