importReact, { useState, useEffect } from'react'; functionMyComponent() { const [data, setData] = useState(null); // 定义异步函数,从 API 获取数据 asyncfunctionfetchData() { const response = await fetch('https://jsonplaceholder.typicode.com/todos/1'); const json = await response.json();...
a JavaScript function can be expressed as lambda (arrow function). That's why a Function Component is sometimes called Arrow Function Components (or maybe also Lambda Function Component). Let's see our refactored React Component with an Arrow Function: ...
用于按需加载组件,功能类似于 react-loadable 封装出这样一个函数的目的实际上是为了提升性能 代码层面实际上就是让 componentDidMount这个钩子异步执行,没挂载组件的时候,component一直是null,不影响页面,挂载后,触发钩子,给state.component赋值,之后render importReact,{Component}from"react";exportdefaultfunctionasyncComp...
functionasyncComponent(importComponent) {classAsyncComponentextendsReact.Component{render() {returnthis.state.component; } state = {component:null}asynccomponentDidMount() {const{default:Component} =awaitimportComponent();this.setState({component:<Component{...this.props}/>}); } }returnAsyncComponent;...
functionFutureAsyncComponent (){const userInfo = getUserInfo()return{userInfo.name};}/* 未来的异步模式 */exportdefaultfunctionHome(){return<React.Suspense fallback={ loading... } ><FutureAsyncComponent/></React.Suspense>} 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12....
创建一个js 文件,如:src/components/AsyncComponent.js,代码如下 复制 import React, { Component }from'react';exportdefaultfunctionasyncComponent(importComponent) {class AsyncComponent extends Component {constructor(props) {super(props);this.state = {component:null,};}async componentDidMount() {const {...
revalidate: Triggers a revalidation for all instances of the component. data: Represents the data fetched by theloader()function. constTodoList=view(// loader functionasync()=>{constres=awaitfetch("https://jsonplaceholder.typicode.com/todos");consttodos=awaitres.json();returntodos;},// render...
仿照react-loadable完成异步组件. Contribute to laowo/react-async-component development by creating an account on GitHub.
比如一个公用的组件,数据来源可能是父组件传过来,又或者是自己主动通过网络请求获取数据。这时候可以先定义一个纯展示型的 Function Component,然后再定义一个高阶组件去获取数据: 代码语言:javascript 复制 functionComp(){...}classHOCextendsPureComponent{asynccomponentDidMount(){constdata=awaitfetchData();this.set...
componentDidUpdate(prevProps,prevState){/** * state 改变,重新请求 * PS: 细心的你可能发现这里又跟旧的 state 比较了一次 */if(prevState.productId!==this.state.productId){this.getProductDetailRequest();}}getProductDetailRequest=async()=>{const{productId}=this.state;// 用更新后的 productId 去...