我正在为多 channel 聊天应用创建一个 React/Redux 前端。在使用 redux、react-redux 和 redux-thunk 时，我在让一些 React 组件在状态更改后重新呈现时遇到问题。

我相信我的 reducer 是不可变的，并且我是通过 react-redux 的 connect 订阅的。当我运行应用程序并查看浏览器控制台时，我看到了组件的初始呈现(即具有初始的空状态)，然后是状态更改(由 index.js 中的 Action 调度触发) .... 然后我希望组件使用新 Prop 重新渲染，但它没有发生。

我在这里放了一个 repo 协议(protocol): https://github.com/mattmoss/react-redux-no-update

node_modules 不在 repo 中，所以要运行，首先下载依赖项(运行 yarn 就足够了)，然后 npm start。

一些摘录(请参阅 repo 中的完整源代码):

reducers/channelList.js

import * as c from '../actions/constants';

export default function channelList(state = [], action) {
    switch (action.type) {
        case c.FETCH_CHANNELS_SUCCESS:
            return action.channels;
        default:
            return state;
    }
}

actions/channelActions.js

export function fetchChannels() {
    return (dispatch) => {
        return ChannelApi.allChannels()
            .then(channels => dispatch(fetchChannelsSuccess(channels)))
            .catch(error => { throw(error); });
    };
}

export function fetchChannelsSuccess(channels) {
    return {
        type: c.FETCH_CHANNELS_SUCCESS,
        channels
    };
}

组件/ChannelListView.js

class ChannelListView extends React.Component {
    render() {
        const { channels, current, onSelect } = this.props;

        console.log("channels:", channels, "current:", current);

        return (
            <ListGroup>
                {channels.map(channel =>
                    <ListGroupItem
                        key={channel.id}
                        active={channel.id === this.props.current}
                        onClick={onSelect(channel.id)}
                    >
                        <strong>#{channel.name}</strong>
                    </ListGroupItem>
                )}
            </ListGroup>
        );
    }
}

export default ChannelListView;

容器/ChannelList.js

import ChannelListView from '../components/ChannelListView';

const mapStateToProps = (state, ownProps) => {
    return {
        channels: state.channelList,
        current: state.currentChannel
    };
};

const mapDispatchToProps = (dispatch) => {
    return {
        onSelect: (id) => () => {}
    };
};

export default connect(mapStateToProps, mapDispatchToProps)(ChannelListView);

App.js

class App extends Component {
  render() {
    return (
      <Grid>
        <Row>
          <Col>
            <h1>Channels</h1>
            <ChannelList />
          </Col>
        </Row>
      </Grid>
    );
  }
}

index.js

const store = configureStore();
store.dispatch(fetchChannels());

ReactDOM.render(
    <Provider store={configureStore()}>
        <App />
    </Provider>,
    document.getElementById('root')
);

商店/configureStore.js

import { createStore, applyMiddleware } from 'redux';
import rootReducer from '../reducers/rootReducer';
import thunk from 'redux-thunk';
import logger from 'redux-logger';

export default function configureStore() {
    return createStore(
        rootReducer,
        applyMiddleware(thunk, logger)
    );
}

最佳答案

我不是 100%，因为我自己对 React 还是比较陌生。但是看看你的 index.js 脚本。

// You configure the store, then dispatch the fetchChannels action
const store = configureStore();
store.dispatch(fetchChannels());

ReactDOM.render(
    // But here, you're recreating the store again, which I think will re-initialise an empty store
    // Change this to use the `store` variable from above.
    <Provider store={configureStore()}>
        <App />
    </Provider>,
    document.getElementById('root')
);

关于javascript - react 组件已连接，redux 状态发生变化......但组件没有更新？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43880915/