此问题似乎重复,但并非如此。我理解该错误,并且已经解决了此类错误,但这次我无法弄清是什么导致了无限循环。
这是导致错误的react组件的代码:
import React, { Component } from 'react';
import { Redirect } from 'react-router-dom';
import PropTypes from 'prop-types';
import './Login.scss';
import axios from 'axios';
import { endPoint } from '../App/path';
import { logIn, isLoggedIn } from '../App/TokenStore';
const re = /^[a-zA-Z0-9_-]{3,15}$/;
class Login extends Component {
constructor() {
super();
this.state = {
username: '',
password: '',
errorMessage: 'Please Login to proceed!',
};
}
onUserNameChange = (e) => {
this.setState({ username: e.target.value });
}
onPasswordChange = (e) => {
this.setState({ password: e.target.value });
}
onFormSubmit = (event) => {
event.preventDefault();
const { username, password } = this.state;
const { history } = this.props;
const isUserNameValid = re.test(String(username).toLowerCase());
if (isUserNameValid) {
axios.post(`${endPoint}/login.json`, { username, password })
.then((response) => {
if (response.status === 200) {
if (response.statusText === 'OK') {
this.setState({
username: '', password: '', errorMessage: '',
});
if (response.config.data) {
console.log(response);
logIn(response.config.data, 'response.config.data.password');
history.push('/dashboard');
} else {
throw new Error();
}
} else {
this.setState({ errorMessage: 'Please enter valid credential!' });
}
}
}).catch((err) => {
if (err.response) {
this.setState({ errorMessage: 'Please enter valid username!' });
} else {
this.setState({ errorMessage: 'Unknown Error!!' });
}
});
} else {
this.setState({ errorMessage: 'Please enter valid username!' });
}
}
render() {
if (isLoggedIn()) {
return <Redirect to="/dashboard" />;
}
const {
username, password, errorMessage,
} = this.state;
return (
<div className="Login">
<form className="Form" onSubmit={this.onFormSubmit}>
<p className="errorMessage">{errorMessage}</p>
<div className="form__group">
<label id="username" className="Label" htmlFor="username">
<i className="fa fa-user" />
<b>Username</b>
</label>
<input
value={username}
onChange={e => this.onUserNameChange(e)}
id="username"
type="username"
placeholder="Your username"
required
/>
</div>
<div className="form__group">
<label id="password" className="Label" htmlFor="password">
<i className="fa fa-key" />
<b>Password</b>
</label>
<input
value={password}
onChange={e => this.onPasswordChange(e)}
id="password"
type="password"
placeholder="Your Password"
required
/>
</div>
<button type="submit" className="Btn">LOGIN</button>
</form>
</div>
);
}
}
Login.propTypes = {
history: PropTypes.shape(),
};
Login.defaultProps = { history: {} };
export default Login;
这些是我在上述组件中使用的其他功能:
export const logIn = (username, token) => {
sessionStorage.setItem('username', username);
sessionStorage.setItem('loggedIn', true);
sessionStorage.setItem('token', token);
};
export const isLoggedIn = () => Boolean(sessionStorage.getItem('loggedIn'));
这是仪表板组件
import React from 'react';
import { NavLink } from 'react-router-dom';
import './Dashboard.scss';
const dashboard = () => (
<div className="container">
<div className="row">
<div className="card col-5 mr-auto ml-auto">
<h5 className="card-header">Lorem ipsum</h5>
<div className="card-body">
<h5 className="card-title">Lorem ipsum</h5>
<p className="card-text">Lorem ipsum</p>
<NavLink to="/dashboard/VRlist" className="btn btn-dashboard">Update/Delete</NavLink>
</div>
</div>
<div className="card col-5 mr-auto ml-auto">
<h5 className="card-header">Lorem ipsum</h5>
<div className="card-body">
<h5 className="card-title">Lorem ipsum</h5>
<p className="card-text">Lorem ipsum</p>
<NavLink to="/dashboard/registration" className="btn btn-dashboard"> Registration</NavLink>
</div>
</div>
</div>
</div>
);
export default dashboard;
这是我的主要应用程序组件
import React from 'react';
import { Switch, Route } from 'react-router-dom';
import Navbar from './Navbar/Navbar';
import Login from './Login/Login';
import Dashboard from './Dashboard/Dashboard';
import { isLoggedIn } from './App/TokenStore';
import VRlist from './VRlist/VRlist';
import NewRegistration from './newRegistration/newRegistration';
import UpdateRegistration from './updateRegistration/updateRegistration';
const App = () => {
if (!isLoggedIn()) {
return (
<div>
<Navbar />
<Route component={Login} />
</div>
);
}
return (
<div>
<Navbar />
<Switch>
<Route exact path="/" component={Login} />
<Route path="/dashboard/VRlist/edit/:id" component={UpdateRegistration} />
<Route path="/dashboard/VRlist" component={VRlist} />
<Route path="/dashboard/registration" component={NewRegistration} />
<Route path="/dashboard" component={Dashboard} />
<Route component={Login} />
</Switch>
</div>
);
};
export default App;
现在,当我运行应用程序并进行登录时,此错误仅在当前选项卡中的第一次登录时才会发生,如果刷新页面,该错误将消失。
答案 0 :(得分:0)
显然,我使用了react-router和react-router-dom版本5,这是在调用history.push()时导致无限渲染循环的原因,但是对于其余组件'history.push( )'工作正常,但登录页面。尽管切换到版本4.3.1完全发出了问题。