React 错误边界不适用于 React

Question

这是我的错误边界文件 -

class ErrorHandling extends Component {
    state = { hasError: false }

    componentDidCatch() {
        this.setState({ hasError: true })
    }

    render() {
        // debugger
        if (this.state.hasError) {
            return <div>Error in Component</div>
        }
        return this.props.children
    }
}

而另一个文件是-

import React, { Component } from 'react';

// Intentionally I have added syntax error below 'd'

function Intermediate(props) {
    return <h1>hi</h1>;d
}
export default Intermediate

在我的 App.js

<ErrorHandling>
  <Intermediate />
</ErrorHandling>

它导致应用程序在未捕获错误的情况下中断。这是在浏览器屏幕上看到的错误

更详细的版本在这里- https://codepen.io/meghana1991/pen/abojydj?editors=0010

当我在本地使用相同的代码处理上面列出的多个文件时，它不起作用

Answer 1

您无法捕获编译时错误，Error Boundaries 用于 UI.

中的运行时错误

参考Compile time vs run time errors.

此外，您必须 use getDerivedStateFromError 才能在回退时添加额外的渲染 UI:

class ErrorBoundary extends React.Component {
  state = {
    hasError: false,
    error: { message: '', stack: '' },
    info: { componentStack: '' }
  };

  static getDerivedStateFromError = error => {
    return { hasError: true };
  };

  componentDidCatch = (error, info) => {
    this.setState({ error, info });
  };

  render() {
    const { hasError, error, info } = this.state;
    const { children } = this.props;

    return hasError ? <ErrorComponent/> : children;
  }
}

为了检查您的 ErrorBoundary，从组件树中的 a reachable 部分抛出错误 which is not:

事件处理程序
异步代码（例如 setTimeout 或 requestAnimationFrame 回调）
服务器端渲染
在错误边界本身（而不是它的子边界）中抛出的错误

const ButtonComponent = () => {
  throw Error("error!");
  return <></>;
};

Note: In development env you will always see the error overlay unless you turn it off or close it with the X button.

完整示例：

const ErrorComponent = () => {
  return <h1>Something went wrong</h1>;
};

class ErrorBoundary extends React.Component {
  state = {
    hasError: false,
    error: { message: "", stack: "" },
    info: { componentStack: "" }
  };

  static getDerivedStateFromError = error => {
    return { hasError: true };
  };

  componentDidCatch = (error, info) => {
    this.setState({ error, info });
  };

  render() {
    const { hasError, error, info } = this.state;
    console.log(error, info);
    const { children } = this.props;

    return hasError ? <ErrorComponent /> : children;
  }
}

const ButtonComponent = () => {
  throw Error("error!");
  return <></>;
};

const App = () => {
  return (
    <ErrorBoundary>
      <ButtonComponent />
    </ErrorBoundary>
  );
};

Answer 2

问题是：您在 React 文档示例中看到的漂亮回退 UI 只出现在 生产中 。所以你必须运行 create-react-app 建议的（你使用它）命令：

npm run build
# wait for it to finish
serve -s build

然后在浏览器中打开 localhost:5000（如果您在提到的终端中看到此地址）。这样 React 文档示例就可以正常工作了。

React 错误边界不适用于 React

React Error Boundaries not working with React

javascript

reactjs

react-hooks

react-error-boundary