import { useReducer } from 'react'; import AddTask from './AddTask.js'; import TaskList from './TaskList.js'; export default function TaskApp() { const [tasks, dispatch] = useReducer( tasksReducer, initialTasks ); function handleAddTask(text) { dispatch({ type: 'added', id: nextId++...
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...
function reducer(state, action) { switch (action.type) { case 'increment': return { count: state.count + 1 }; case 'decrement': return { count: state.count - 1 }; default: throw new Error(); } } function Counter() { const [state, dispatch] = React.useReducer(reducer, initialState...
export default function test (state = initialState, action) { state = JSON.parse(JSON.stringify(state)); // <- 这里每次reducer执行都会重新生成新的对象,而且Redux只要触发dispatch,整个reducer树都会被重新执行,所以这里可能会导致没有意义重新渲染 switch (action.type) { case TYPES.TEST: let { Result...
export function injectAsyncReducer(store, name, asyncReducer) { store.asyncReducers[name] = asyncReducer; store.replaceReducer(createReducer(store.asyncReducers)); } 路由.js import { injectAsyncReducer } from './store'; // Assuming React Router here but the principle is the same ...
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 (...
1、创建action/actionCreator.js import { createAction } from 'redux-actions'; export const addnum = createAction('ADDNUM') 2、组件中引入使用 import React,{Component} from "react"; import store from "./store" import {addnum} from "./action/actionCreator" export default class App extends ...
import { useReducer } from 'react'; import AddTask from './AddTask.js'; import TaskList from './TaskList.js'; export default function TaskApp() { const [tasks, dispatch] = useReducer( tasksReducer, initialTasks ); function handleAddTask(text) { dispatch({ type: 'added', id: nextId++...
推荐的腾讯云相关产品:在腾讯云中,可以使用Serverless Cloud Function(SCF)来构建和部署使用Reducer的React应用程序。SCF是一种无服务器计算服务,可提供按需运行的计算能力。 产品介绍链接地址:https://cloud.tencent.com/product/scf 请注意,以上答案中没有提及亚马逊AWS、Azure、阿里云、华为云、天翼云、GoDaddy、Namechea...
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"; ...