"Maximum update depth exceeded" 反应和反应 cookie 错误

Question

我按照本教程使用 Redux 在 React 中实现了一个简单的登录表单：https://jslancer.com/blog/2017/04/27/a-simple-login-flow-with-react-and-redux/

一切正常，但是当我添加 cookie 时出现错误：

Warning: Cannot update during an existing state transition (such as within render). Render methods should be a pure function of props and state.

还有：

Uncaught Invariant Violation: Maximum update depth exceeded. This can happen when a component repeatedly calls setState inside componentWillUpdate or componentDidUpdate. React limits the number of nested updates to prevent infinite loops.

我做了一些调试，如果我从下面代码的输入中删除 onChange={e => this.setState({password: e.target.value})}，错误就会消失。

知道为什么以下代码不起作用吗？

import { connect } from 'react-redux';
import { withCookies } from 'react-cookie'

class LoginForm extends Component {

  constructor(props) {
    super(props);
    this.state = {
      username: '',
      password: ''
    };
  }

  render() {
    let {username, password} = this.state;
    let { cookies, allCookies, isLoginPending, isLoginSuccess, loginError} = this.props;
    cookies.set('username', 'Ross', { path: '/', secure: true, httpOnly: true});
    console.log(cookies.get('username'));
    return (
      <form name="loginForm" onSubmit={this.onSubmit}>
        <div className="form-group-collection">
          <div className="form-group">
            <label>Username:</label>
            <input type="text" name="username" onChange={e => this.setState({username: e.target.value})} value={username}/>
          </div>
          <div className="form-group">
            <label>Password:</label>
            <input type="password" name="password" onChange={e => this.setState({password: e.target.value})} value={password}/>
          </div>
        </div>
      </form>
    )
  }
}

const mapStateToProps = (state) => {
  return {
    isLoginPending: state.isLoginPending,
    isLoginSuccess: state.isLoginSuccess,
    loginError: state.loginError,
  };
}

export default withCookies(connect(mapStateToProps, null)(LoginForm));```

Answer 1

我的猜测是，因为您的组件连接到 cookie HoC，然后您在 render 方法中调用 cookies.set，所以它每次都会自我更新，从而形成无限循环。请尝试将 cookies.set 移动到 componentDidMount。

"Maximum update depth exceeded" 反应和反应 cookie 错误

"Maximum update depth exceeded" error in react and react-cookie

reactjs

react-redux

react-cookie