Question

我一直在尝试在React中实现 ErrorBoundary 。我只是在App.js中创建了一个称为counter组件的计数器。如果计数器的值小于0，则会引发错误。作为后备UI，我制作了错误边界组件来处理错误（如果存在）。

当我将计数器的值从0减小时，我的errorBoundary组件似乎可以工作一秒钟。一秒钟，它显示了用于错误处理目的的预期后备UI。但是就在那之后，整个react应用都崩溃了。

我正在附上屏幕截图： crashed app screenshot fallbackUI screenshot

ErrorBoundary.js

import React, { Component } from "react";

class ErrorBoundary extends Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false, error: null, errorInfo: null };
  }
  static getDerivedStateFromError(error) {
    console.log("here getDerivedStateFromError");
    // Update state so the next render will show the fallback UI.
    return { hasError: true };
  }
  componentDidCatch(error, errorInfo) {
    console.log("here did catch");
    // You can also log the error to an error reporting service
    // logErrorToMyService(error, errorInfo);
    this.setState({
      error: error,
      errorInfo: errorInfo,
      hasError: true
    });
  }

  render() {
    console.log("Inside Error Boundary render Function");

    return this.state.error ? (
      <h1> Something Went Wrong ... Error Boundary Caught it!</h1>
    ) : (
      <>
        {this.props.children}
      </>
    );
  }
}
export default ErrorBoundary;

Counter.js

import React, { Component } from "react";

class Counter extends Component {
  constructor(props) {
    super(props);
    this.state = {
      value: 0
    };
  }
  addValue = () => {
    this.setState({
      value: this.state.value + 1
    });
  };

  subValue = () => {
    this.setState({
      value: this.state.value - 1
    });
  };

  render() {
    if (this.state.value < 0) {
      throw new Error("Simulating React App Crash!");
    } else {
      return (
        <>
          <p>{this.state.value}</p>
          <button onClick={this.addValue}>+</button>
          <button onClick={this.subValue}>-</button>
        </>
      );
    }
  }
}

export default Counter;

App.js

import React from "react";
import logo from "./logo.svg";
import "./App.css";
import Counter from "./components/Counter";
import ErrorBoundary from "./components/ErrorBoundary";

function App() {
  return (
    <div className="App">
      <div>
        <ErrorBoundary>
          <Counter />
          <p>Here if the value counter value goes below 0, it throws error.</p>
        </ErrorBoundary>
      </div>
      <hr></hr>
      <div>
        <ErrorBoundary>
          <Counter />
          <p>Here if the value counter value goes below 0, it throws error.</p>
        </ErrorBoundary>
      </div>
      <hr></hr>
      <div>
        <ErrorBoundary>
          {" "}
          <Counter />
          <Counter />
        </ErrorBoundary>

        <p>Here anyone of the two counter value goes below 0, both of them throws error together.</p>
      </div>
      <hr></hr>
      <div>
        <Counter />
        <p>Without any Error Boundary. It will crash whole App if counter is less than 0</p>
      </div>

      <header className="App-header">
        <img src={logo} className="App-logo" alt="logo" />
        <p>
          Edit <code>src/App.js</code> and save to reload.
        </p>
        <a className="App-link" href="https://reactjs.org" target="_blank" rel="noopener noreferrer">
          Learn React
        </a>
      </header>
    </div>
  );
}

export default App;

Answer 1

该代码在SnackExpo对我有用。安装的软件包中可能存在版本不兼容

React JS错误边界似乎无法捕获错误

1 个答案: