Most of the time, your components respond to events that occur within the component tree by defining their own handler or by accepting a handler defined by a parent component via props. Sometimes, this isn't enough. In this lesson, we'll rely on life…

React.createClass和extends Component的区别主要在于: 语法区别 propType 和 getDefaultProps 状态的区别 this区别 Mixins 语法区别 React.createClass import React from 'react'; const Contacts = React.createClass({ render() { return ( <div></div> ); } }); export default Cont…

React Native中的component跟Android中的activity,fragment等一样,存在生命周期,下面先给出component的生命周期图 getDefaultProps object getDefaultProps() 执行过一次后,被创建的类会有缓存,映射的值会存在this.props,前提是这个prop不是父组件指定的 这个方法在对象被创建之前执行,因此不能在方法内调用this.props ,另外,注意任何getDefaultProps()返回的对象在实例中共享,不…

一.它们几乎完全相同,但是PureComponent通过prop和state的浅比较来实现shouldComponentUpdate,某些情况下可以用PureComponent提升性能 1.所谓浅比较(shallowEqual),即react源码中的一个函数,然后根据下面的方法进行是不是PureComponent的判断,帮我们做了本来应该我们在shouldComponentUpdate中做的事情 if (this._compositeType === CompositeTypes.PureCla…

目录(?)[-] 创建Menu MenuItem的属性itemId MenuItem的属性groupId MenuItem的属性orderId MenuItem的属性可选属性 Menu触发 onOptionItemSelected Click Listener 使用Intent 每个Activity都关联一个且是唯一一个menu对象,当对该menu进行创建,将触发onCreateOptionsMenu(). 创建Menu 我们通过下面简单的例子来阐述menu的各个属性. public class…

To show a list of unchanging data in React Native you can use the scroll view component. In this lesson, we'll map through the data we got back from the Github API, and fill complete ScrollView component for the user profile. After call goToProfile f…

Here we refactor a React TypeScript class component to a function component with a useState hook and discuss how props and state types can be modeled accordingly. import * as React from "react"; import { render } from "react-dom"; impo…

We have a render prop based class component that allows us to make a GraphQL request with a given query string and variables and uses a GitHub graphql client that is in React context to make the request. Let's refactor this to a function component th…

react.js javascript 3 之前翻译了两篇关于Container&Presentational Component模型的文章,一篇是基础的Container和Component的定义,另外一篇是进阶版,因为翻译的太烂,感觉有很多错误,所以只放原文链接. 在这里我想讨论一下我自己对这个模型的一些想法. 注:便于书写,下面统一把Container&Presentational Components模型翻译为容器&展示组件模型 注:下面图片中的components文件夹指…

If you’ve created several Routes within your application, you will also want to be able to navigate between them. React Router supplies a Link component that you will use to make this happen. Import Link: import { BrowserRouter as Router, Route, Link…