import AddTask from './AddTask.js'; import TaskList from './TaskList.js'; import { TasksProvider } from './TasksContext.js'; export default function TaskApp() { return ( <TasksProvider> Day off in Kyoto <AddTask /> <TaskList /> </TasksProvider> ); } 你也可以从 TasksContext.js...
import{ useReducer }from'react';importAddTaskfrom'./AddTask.js';importTaskListfrom'./TaskList.js';importtasksReducerfrom'./tasksReducer.js';exportdefaultfunctionTaskApp() {const[tasks, dispatch] =useReducer(tasksReducer, initialTasks);functionhandleAddTask(text) {dispatch({type:'added',id: nextId...
export default function createReducer(asyncReducers) { return combineReducers({ users, posts, ...asyncReducers }); } 商店.js import { createStore } from 'redux'; import createReducer from './reducers'; export default function configureStore(initialState) { const store = createStore(createReducer()...
import{ADD,MINUS}from'../constants/counter'constINITIAL_STATE={num:0}exportdefaultfunctioncounter(state=INITIAL_STATE,action){switch(action.type){caseADD:return{...state,num:state.num+1}caseMINUS:return{...state,num:state.num-1}default:returnstate}} counter本质是一个函数,第一个参数为state,也...
为什么 reducer 是一个纯函数 纯函数是什么 纯函数是这样一种函数，即相同的输入，永远会得到相同的输出，而且没有任何可观察的副作用。可观察的副作用 进行一个 HTTP 请求Mutating data输出数据到屏幕或者控制台DOM 查询/操作Math.random()获取的当前时间 例子 function priceAfterTax(productPrice) { return (...
if (typeof producer !== 'function') throw new Error('producer must be a function') this.producer = producer } on (f) { if (Object.prototype.hasOwnProperty.call(this, 'data') || Object.prototype.hasOwnProperty.call(this, 'error')) { ...
Route Components 是指./src/routes/目录下的文件,他们是./src/router.js里匹配的 Component。 通过connect 绑定数据 比如: import {connect }from'dva';functionApp() {}functionmapStateToProps(state,ownProps) {return { users:state.users, };
function reducer(state, action) { switch (action.type) { case 'increment': return { count: state.count + 1 }; case 'decrement': return { count: state.count - 1 }; case 'reset': return init(action.payload); default: throw new Error(); ...
TypeError: react__WEBPACK_IMPORTED_MODULE_2___default(...) is not a function 我如何解决这个问题?我在下面添加了代码。 dispatch()正在下面的组件中调用 import authAction from "../store/Auth"; import { useDispatch } from "react-redux"; ...
2.创建store/reducer.js文件 2.1不拆分 import {ADD,REDUCE,PUSHARR,POPARR}from './constants.js' const initState={ counter:1, arr:[111,222,333] } function reducer(state=initState,action){ switch (action.type) { case ADD: return {...state,counter:state.counter+action.speed} case REDUCE: ...