React-redux存储状态和mapStateToProps状态不同的原因是什么？

Question

我遇到一种情况，当我调度一个动作时，存储状态会发生应有的变化，但是我连接的组件mapStateToProps回调状态未反映出存储中的新更改。可能是什么原因呢？configureStore.jsexport default () => {    const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;    const store = createStore(        combineReducers({            concepts: conceptReducer,            conceptModal: conceptModalReducer,            cards: cardReducer,            cardModal: cardModalReducer,        }),        composeEnhancers(applyMiddleware(queryApi))    );    store.subscribe(() => {        console.log('store notification:', store.getState());    })    return store;};Reducer.jscase "UPDATE_CONCEPT_SUCCESS": {    let concepts = [...state.data].map((concept) => {        if (concept.id === action.id) {            return { ...concept, ...action.concept };        }        return concept;    });    /* Even with return below, mapStateToProps state parameter still returns the old state */    // return {'data': [{id:1},{id:2}]}    return { ...state, pending: false, lastErrorCode: null, lastErrorMessage: null, data: concepts };    break;}CardModal.jsexport default connect((state, p) => (() => {    // the console.log below returns the old state    console.log('connect called', state);    return ({        isThemeDark: state.common.isThemeDark,        allConceptsData: allConcepts(state.concepts.data),        conceptsData: allConceptsForTopicId(state.concepts.data, state.cardModal.topicId),    })}))(CardModal);

Answer 1

您的mapStateToProps返回一个函数，而不是新状态。

尝试以下方法：

export default connect((state, p) => {

  // the console.log below returns the old state

  console.log('connect called', state);

  return {

    isThemeDark: state.common.isThemeDark,

    allConceptsData: allConcepts(state.concepts.data),

    conceptsData: allConceptsForTopicId(state.concepts.data, state.cardModal.topicId),

  };

}))(CardModal);