Redux-saga 从动作中获取数据返回 patternOrChannel 未定义

在检查时未捕获(patternOrChannel):patternOrChannel未定义在 rootSaga 未捕获到 rootSagaat takeEvery错误:take(patternOrChannel):patternOrChannel 未定义屏幕代码:import { checkUserLoginStatus, userSignin } from '../actions/user';类 PreCheckout 扩展 PureComponent {handleLogin = () =>{this.props.dispatch(userSignin(username, password));};使成为() { .......操作:const USER_SIGNIN = 'USER_SIGNIN';export const userSignin = (用户名，密码) =>({类型:USER_SIGNIN，用户名，密码，});减速器:import {CHECK_USER_LOGIN_STATUS,USER_SIGNIN,USER_SIGNIN_RESULT，USER_SIGNIN_ERROR，} 来自'../actions/user';常量初始状态 = {isLoggedIn: 假,isFetching:假，信息: {}，错误:空，};const reducer = (state = initialState, action) =>{开关(动作.类型){案例 CHECK_USER_LOGIN_STATUS:返回 {...状态，};案例 USER_SIGNIN:返回 {...状态，isFetching: 真,};案例 USER_SIGNIN_RESULT:返回 {...状态，isFetching:假，信息:action.result，};案例 USER_SIGNIN_ERROR:返回 {...状态，isFetching:假，错误:action.error，};Redux-Saga:import {USER_SIGNIN,USER_SIGNIN_RESULT，USER_SIGNIN_ERROR，} 来自'../actions/user';函数* fetchUserInformation(action) {尝试 {console.log('fetchUserInformation action:', action);const response = yield call(login, action);收益率放置({类型:USER_SIGNIN_RESULT，结果:response.result，});}赶上(e){收益率放置({类型:USER_SIGNIN_ERROR，错误:e.message，});}}导出默认函数* rootSaga() {产量 takeEvery(USER_SIGNIN, fetchUserInformation);} 解决方案 正如我在评论中提到的.您只是忘记导出常量.应该是export const USER_SIGNIN = 'USER_SIGNIN';或const USER_SIGNIN = 'USER_SIGNIN';...出口{ USER_SIGNIN };eslint 可以使用 eslint-plugin-import 和这个 捕获这些类型的错误-plugin-import/blob/HEAD/docs/rules/named.md" rel="noreferrer">规则 已启用.I need to send dynamic data from my screen to action/reducer and fetch data from API with that data, but when i yield in my rootSaga i'll get an error like this: uncaught at check take(patternOrChannel): patternOrChannel is undefined uncaught at rootSaga at rootSaga at takeEvery Error: take(patternOrChannel): patternOrChannel is undefinedScreen code:import { checkUserLoginStatus, userSignin } from '../actions/user';class PreCheckout extends PureComponent { handleLogin = () => { this.props.dispatch(userSignin(username, password)); }; render() { .......Action:const USER_SIGNIN = 'USER_SIGNIN';export const userSignin = (username, password) => ({ type: USER_SIGNIN, username, password,});Reducer:import { CHECK_USER_LOGIN_STATUS, USER_SIGNIN, USER_SIGNIN_RESULT, USER_SIGNIN_ERROR,} from '../actions/user';const initialState = { isLoggedIn: false, isFetching: false, information: {}, error: null,};const reducer = (state = initialState, action) => { switch (action.type) { case CHECK_USER_LOGIN_STATUS: return { ...state, }; case USER_SIGNIN: return { ...state, isFetching: true, }; case USER_SIGNIN_RESULT: return { ...state, isFetching: false, information: action.result, }; case USER_SIGNIN_ERROR: return { ...state, isFetching: false, error: action.error, };Redux-Saga:import { USER_SIGNIN, USER_SIGNIN_RESULT, USER_SIGNIN_ERROR,} from '../actions/user';function* fetchUserInformation(action) { try { console.log('fetchUserInformation action: ', action); const response = yield call(login, action); yield put({ type: USER_SIGNIN_RESULT, result: response.result, }); } catch (e) { yield put({ type: USER_SIGNIN_ERROR, error: e.message, }); }}export default function* rootSaga() { yield takeEvery(USER_SIGNIN, fetchUserInformation);} 解决方案 As I have mention in comment. You simply forgot to export the constant.Should be export const USER_SIGNIN = 'USER_SIGNIN';Orconst USER_SIGNIN = 'USER_SIGNIN';...export { USER_SIGNIN };These types of bugs could be captured by eslint using eslint-plugin-import with this rule enabled. 这篇关于Redux-saga 从动作中获取数据返回 patternOrChannel 未定义的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！