reactjs - 如何仅更新 1 个字段而不覆盖 React Hooks 上的嵌套对象上的其他字段使用 Reducer？

Question

我开始学习 React + hooks。我现在正在使用 useReducer。但是我在更新我的 useReducer 状态时遇到了问题。每次我想更新对象状态的 1 个字段时，所有其他字段都会被删除。

我的解决方案是将所有现有值传递给它们，即使我只需要更新 1 个字段。有没有更有效的方法来做到这一点？

这是我的解决方案：

const initialState = {
    filter: {
        text: "Filter",
        list: [],
        isActive: false,
        message: "",
    },
    apiList: []
};

const reducer = (state, action) => {
  switch (action.type) {
    case "SET_FILTER_LIST":
      return {
        ...state,
        filter: { ...state.filter,
            list: action.payload.list,
            isActive: action.payload.isActive,
            message: action.payload.message,
            text: action.payload.text,
        }
      };

    default:
      return state;
  }
};
//BELOW - I just want to pass the e.target.textContent to text field. To avoid deleting the other fields. I re-pass all the existing value so it wont get deleted.

  const onSelect = e => {
      let filter = e.target.textContent;

      dispatch({
        type: 'SET_FILTER_LIST',
        payload: {
            list: state.filter.list,
            text: filter,
            message: state.filter.message,
            isActive: state.filter.isActive
        }
      });
  };

Answer 1

您可以使用以下代码：

return {
    ...state,
    filter: {
        ...state.filter,
        ...action.payload,
    }
};

Answer 2

如果我理解你，你已经有了一些答案：

return {
    ...state,
    filter: {
        ...state.filter,
        text: action.payload
    }
}

然后只将文本字段传递到有效负载中