Question

要在成功登录后访问主页，用户需要刷新整个页面（否则他将不会自动重定向到主页）。可能的问题是什么，如何解决？这是我的源代码：

App.js

class App extends Component {
  render() {
    return (
      <BrowserRouter>
       <Switch>
            <Route path='/' exact component={ MainPage }></Route>
            <Route path='/login' component={ LogIn }></Route>
            <Route component={ NotFoundPage }></Route>
       </Switch>
      </BrowserRouter>
    );
  }
}

export default App;

LogIn.js

const userIdRegex = RegExp(
  /^[uU]*1+[0-9]*$/
);

class LogIn extends Component {

  constructor(props) {
    super(props);

    this.state = {
      userId: null,
      password: null,
      fullName: undefined,
      responseError: false,
      loggedIn: false,
      formErrors: {
        userId: "",
        password: ""
      }
    };
    this.handleChange = this.handleChange.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  handleChange = e => {
    e.preventDefault();
    const { name, value } = e.target;
    let formErrors = { ...this.state.formErrors };

    switch (name){

      case "userId":
        formErrors.userId = userIdRegex.test(value)
          ? ""
          : "Invalid user ID";
        break;
      case "password":
        formErrors.password =
          value.length < 8 ? "Invalid password" : "";
        break;
      default:
        break;
    }

    this.setState({ formErrors, [name]: value }, () => console.log(this.state));
  };

  handleSubmit = e => {
      e.preventDefault();

      axios.post('url', { userId: e.target.elements.userId.value,
      password: e.target.elements.password.value })
        .then((response) => {
          if(response.status=200){
            this.setState({ loggedIn: true });
            let responseJSON = response;
            sessionStorage.setItem("userData", responseJSON);
          } else {
            console.log("Log In Error");
          }
        }).catch((error) => {
          console.log(error);
          this.setState({ responseError: true });
        });

  };

  render() {
    if ( this.state.loggedIn ) {
      return (<Redirect to={'/'} />);
    }
    if ( sessionStorage.getItem('userData') ){
      return (<Redirect to={'/'} />);
    }
    const { formErrors } = this.state;
    const responseError = this.state.responseError;
    // const loggedIn = this.state.loggedIn;
    // const { from } = this.props.location.state || '/';

    return (
      <div className="wrapper">
        <div className="form-wrapper">
        <img src={Logo} className="App-logo" alt="Logo" />
        <p>To Log In enter your user ID and password.</p>
          <form onSubmit={this.handleSubmit} noValidate>      
            <div className="userId">
              <input
                autoFocus
                className={formErrors.userId.length > 0 ? "error" : null}
                placeholder="User ID"
                type="text"
                name="userId"
                noValidate
                defaultValue="u"
                onChange={this.handleChange}
              />
              {formErrors.userId.length > 0 && (
                <span className="errorMessage">{formErrors.userId}</span>
              )}
            </div>
            <div className="password">
              <input
                className={formErrors.password.length > 0 ? "error" : null}
                placeholder="Password"
                type="password"
                name="password"
                noValidate
                onChange={this.handleChange}
              />
              {formErrors.password.length > 0 && (
                <span className="errorMessage">{formErrors.password}</span>
              )}
            </div>
            <div className="createAccount">
              <button type="submit" disabled={!this.state.userId} disabled={!this.state.password}>
                Log in
            </button>
            </div>
          </form>
          { responseError==true && (
            <span className="response-error errorMessage">Please enter valid user values</span>
          ) }
        </div>
        </div>
      )}
  }

export default LogIn;

MainPage.js

class MainPage extends Component {

    constructor(props) {
        super(props);
        this.state = {
          redirect: false,
        }
        this.logout = this.logout.bind(this);
        this.componentDidMount = this.componentDidMount.bind(this);
    }

    componentDidMount() {
          if( sessionStorage.getItem('userData') ){
              console.log('User Logged In');
          } else {
            this.setState({redirect: true})
          }
      }

    logout(){
        sessionStorage.setItem('userData', '');
        sessionStorage.clear();
        this.setState({redirect: true})
    }
    render(){
        if (this.state.redirect) {
            return (<Redirect to={'/login'} />);
        }
        return(
        <div>
            <p>Welcome</p>
            <button onClick={this.logout}>Logout</button>
        </div>

        );
    }
}
export default MainPage;

当我从MainPage.js中删除componentDidMount（）方法时，它解决了重定向问题，但是无需通过URL登录即可访问主页。

Answer 1

所有路线组件都可以访问道具中的history对象，因此您可以在成功登录this.props.history.push('/')组件后执行LogIn。

class LogIn extends Component {
  // ...

  handleSubmit = e => {
    e.preventDefault();

    axios
      .post("url", {
        userId: e.target.elements.userId.value,
        password: e.target.elements.password.value
      })
      .then(response => {
        if (response.status === 200) {
          this.setState({ loggedIn: true });
          sessionStorage.setItem("userData", response);
          this.props.history.push("/");
        } else {
          console.log("Log In Error");
        }
      })
      .catch(error => {
        console.log(error);
        this.setState({ responseError: true });
      });
  };

  // ...
}

成功授权后如何立即重定向到主页？

1 个答案: