1 context
2 contextType
3 lazy
4 suspense
5 memo
===========
1 Context 提供了一种方式,能够让数据在组件树中传递而不必一级一级手动传递
API: createContext(defaultValue)
示例1:
import React,{ Component,createContext } from 'react';//在这里导出context函数 import logo from './logo.svg'; import './App.css'; const BatteryContext = createContext();//在这里创建context //孙子组件 class Leaf extends Component { render(){ //在这里定义 consumer 消费者 return ( <BatteryContext.Consumer> { Battery => <h1>BatteryName:{Battery}</h1> } </BatteryContext.Consumer> ) } } //子组件 class Middle extends Component{ render(){ return <Leaf/>; } } //父组件 class App extends Component { render(){ //在这里定义 Provider context的提供者 return ( <BatteryContext.Provider value = {60}> <Middle/> </BatteryContext.Provider> ) } } export default App;