小编Jas*_* Xu的帖子

我有一个普通的选择器,它只是用来获得状态的一部分:

export const getAllPosts = state => {
  return state.posts;
};

如果我使用重新选择来包装选择器:

import { createSelector } from 'reselect';

export const allPosts = createSelector(
  getAllPosts,
  (posts) => posts
);

它是否有任何意义,如提高性能？在我看来,包装是不必要的.

这是我的主要代码？App组件连接到 Redux 的商店：

class App extends Component {
  render() {
    const { requestQuantity } = this.props;
    return (
      <div>
        <Router>
          <Switch>
            <Route exact path="/" component={PostList} />
            <Route path="/login" component={Login} />
            <Route path="/topics" component={PostList} />
          </Switch>
        </Router>
        {requestQuantity > 0 && <Loading />}
      </div>
    );
  }
}

const mapStateToProps = (state, props) => {
  return {
    requestQuantity: getRequestQuantity(state)
  };
};

export default connect(mapStateToProps)(App);

PostList 组件也连接到 Redux 的商店：

class PostList extends Component {
  componentDidMount() {
    this.props.fetchAllPosts();
  }

  render() {
    const …

我getServerSideProps 用来获取初始文章数据，如下所示：

export const getServerSideProps = async () => {\n  const url =\n    "https://conduit.productionready.io/api/articles?limit=10&offset=0";\n  const res = await fetch(url);\n  const resJson = await res.json();\n\n  return {\n    props: {\n      data: resJson.articles\n    }\n  };\n};\n

我需要在页面更改时更新文章\xef\xbc\x8cso我有以下代码：

export default function IndexPage(props) {\n  const { data } = props;\n  const [articles, setArticles] = useState(data);\n  const [page, setPage] = useState(0);\n\n  useEffect(() => {\n    const fetchData = async (page) => {\n      const url = `https://conduit.productionready.io/api/articles?limit=10&offset=${page}`;\n      const res = await fetch(url);\n      const resJson = …