react-native - 从 useEffect 挂钩调度时，Redux 数组状态未更新

Question

我正在尝试在单击按钮时使用钩子更新 react-redux 中的状态。

单击按钮时，它会更新 ordersArray，我需要在 redux 状态下更新该数组。

目前我正在使用下面的代码，我的状态数组保持不变，没有任何变化。

  useEffect(() => {
    if (!_.isEmpty(tempOrders)) {
      //   console.log('tempOrderstempOrders', tempOrders);
      dispatch(storeCartOrders(tempOrders));
    }
  }, [dispatch, tempOrders]);

cartOrderSlice.js

import {createSlice, createAsyncThunk} from '@reduxjs/toolkit';

const slice = createSlice({
  name: 'cartOrder',
  initialState: {
    cartOrders: [],
  },
  reducers: {
    // Redux Toolkit allows us to write "mutating" logic in reducers. It
    // doesn't actually mutate the state because it uses the immer library,
    // which detects changes to a "draft state" and produces a brand new
    // immutable state based off those changes
    storeCartOrders: (state, action) => {
      console.log('action.payload', action.payload) // <-- this payload always has old values 
      state.cartOrders = action.payload;
    },
  },
});

export const {storeCartOrders} = slice.actions;

export default slice.reducer;

• useEffect单击按钮时调用以下内容

• 下面的 useEffect 将setTempOrders依次调用带有函数的useEffect钩子dispath

    useEffect(() => {
  const updateOrders = async () => {
          let rows = [...tempOrders];
    if (currentItemValues) {
            const currentItemIndex = rows.findIndex(
              (row) => row.id === currentItemValues.id,
            ); 
        if (currentItemIndex >= 0) {
          if (currentItemValues.quantity === 0) {
            rows.splice(currentItemIndex, 1);
          } else {
            rows[currentItemIndex]['quantity'] = currentItemValues.quantity;
  
          }
        }
      }
      // console.log('rowsrowsrows', rows);
     // rows[currentItemIndex]['quantity'] is not being changed at all. 
    // and that's why storage and setTempOrders won't change the data. 
       setTempOrders(rows);
      await setLocalCartItems('cart', rows);
    };
  
    if (!_.isEmpty(tempOrders)) {
      updateOrders();
    }
  }, [currentItemValues, toggle]);
  

如果您需要显示更多代码，请告诉我。非常感谢您的帮助！谢谢

当前项目值

有时它会给出如下错误：

Possible Unhandled Promise Rejection (id: 0):
TypeError: Cannot assign to read only property 'quantity' of object '#<Object>'

标签： react-nativereact-reduxreact-hooks

Answer 1

您有一个对象数组，因此您需要执行以下操作

rows[currentItemIndex].quantity = currentItemValues.quantity;