关于React16.0的componentDidCatch方法解读

import React, { Component } from 'react'
export default class App extends Component {
  render() {
    return (
      <div>
        <PointerError>
          <SomeState></SomeState>
        </PointerError>
      </div>
    )
  }
}
class PointerError extends Component {
  // PointerError是错误捕获组件
  constructor(props) {
    super(props)
    this.state = {
      error: false,
      text: ''
    }
  }
  // parseStr(str) {
  // 格式化位置组件错误信息
  //   let res = str.match(/in[^\(]+\(/g)
  //   res = res.map(item => item.slice(3, -2))
  //   console.log('res', res)
  // }
  componentDidCatch(error, info) {
    console.log(error, info)
    alert('错误发生的位置：' + info.componentStack) //错误信息error.message, 错误堆栈error.stack, 组件堆栈info.componentStack
    this.setState({
      error,
      info,
      text: info.componentStack
    })
  }
  render() {
    if (this.state.error) {
      return (
        <div>
          <h1>错误是：{this.state.error.toString()}</h1>
          <h2>错误出现的位置是：{this.state.text}</h2>
          <img src="https://dss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=2942945378,442701149&fm=26&gp=0.jpg" />
        </div>
      )
    }
    return this.props.children
  }
}
class SomeState extends Component {
  constructor(props) {
    super(props)
    this.state = { error: false }
  }
  render() {
    throw new Error('我发生了错误') //报错信息
    return (
      <div>
        <div>你已经正确的打开了页面</div>
      </div>
    )
  }
}

{this.state.info && this.state.info.componentStack}

class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }
  componentDidCatch(error, info) {
    // Display fallback UI
    this.setState({ hasError: true });
    // You can also log the error to an error reporting service
    logErrorToMyService(error, info);
  }
  render() {
    if (this.state.hasError) {
      // You can render any custom fallback UI
      return <h1>Something went wrong.</h1>;
    }
    return this.props.children;
  }
}

<ErrorBoundary>
  <MyWidget />
</ErrorBoundary>

{this.state.info && this.state.info.componentStack}

class App extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      hasError: false
    }
  }
  componentDidCatch(error, info) {
    console.log(error, info)
    this.setState({
      hasError: true
    })
  }
  render() {
    return this.state.hasError ?
      <h2>页面出错了404</h2>
      : (
        <React.Fragment>
          {/* 检验是否有登录信息 */}
          <AutoRoute />
          {/* 有了switch后，匹配到path后就不会再匹配下去了 */}
          <Switch>
            <Route path="/login" component={Login}></Route>
            <Route path='/register' component={Register}></Route>
            <Route path='/chat/:user' component={Chat}></Route>
          </Switch>
        </React.Fragment>
      )
  }
}