ReactJs this.props.history.push（）不起作用

Question

我是Reactjs的新手，出于某种原因，我正在开发一个小型应用程序以进行学习。

我正在使用react-router-dom在不同组件之间导航。

这个想法是当用户单击以注销时，应用程序组件应在componentWillUpdate（）方法中检测到注销事件，然后将用户重定向到“登录组件”。

错误是：

Routes.js

import React from 'react';
import { BrowserRouter, Route, Switch, Link, NavLink } from 'react- 
router-dom';
import Login from '../Components/LoginComponent/Login';
import AddNoteForm from "../Components/AddNoteForm";


const AppRouter = () => (
<BrowserRouter>
        <Switch>
            <Route path="/" component={AddNoteForm} exact={true} />
            <Route path="/login" component={Login} exact={true} />
        </Switch>
</BrowserRouter>
);

export default AppRouter;

Index.js

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import configureStore from './Redux/Store/ConfigureStore';
import './index.css';
import App from './App';
import registerServiceWorker from './registerServiceWorker';
import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';


const store = configureStore();


const jsx = (
<Provider store={store}>
    <MuiThemeProvider>
        <App />
    </MuiThemeProvider>
</Provider>
);

ReactDOM.render(jsx, document.getElementById('root'));
registerServiceWorker();

App.js

import React, { Component } from 'react';
import './App.css';
import { Grid, Col, Row } from 'react-bootstrap';
import Navigation from "./Components/Navigation";
import AddNoteForm from "./Components/AddNoteForm";
import Clock from "./Components/Clock";
import { connect } from 'react-redux';
import AppRoutes from "./Routes/Routes";

class App extends Component {

constructor(props) {
super(props);
}
  componentWillUpdate(nextProps, nextState) {

if (nextProps.store.user.email === null || nextProps.store.user.email 
== undefined) {
  this.props.history.replace('/login');
}

 }


 render() {
 return (
  <div className="App">
    <header className="App-header">
      <h1 className="App-title">Welcome to this Learing React 
Application.</h1>
    </header>
    <div className="App-intro" >
      <Navigation></Navigation>
      <Grid>
        <Row className="show-grid">
          <AppRoutes />
        </Row>
      </Grid>
    </div>
  </div>
  );
 }
}

const mapStateToProps = (store) => {
  return { store };
};

export default connect(mapStateToProps)(App);

Package.json

    {
      "name": "first-react",
      "version": "0.1.0",
      "private": true,
      "dependencies": {
        "install": "^0.11.0",
        "material-ui": "^0.20.0",
        "npm": "^6.0.0",
        "react": "^16.2.0",
        "react-bootstrap": "^0.32.1",
        "react-dom": "^16.2.0",
        "react-redux": "^5.0.7",
        "react-router-dom": "^4.2.2",
        "react-scripts": "1.1.1",
        "react-spinner": "^0.2.7",
        "react-spinners": "^0.3.2",
        "react-toastify": "^4.0.0-rc.5",
        "redux": "^4.0.0",
        "redux-thunk": "^2.2.0",
        "uuid": "^3.2.1"
      },
      "scripts": {
        "start": "react-scripts start",
        "build": "react-scripts build",
        "test": "react-scripts test --env=jsdom",
        "eject": "react-scripts eject"
      }
    }

Answer 1

您的App组件没有被BrowserRouter包装。 您需要像这样包装它：

const Routes = () => (
    <Switch>
        <Route path="/" component={AddNoteForm} exact={true} />
        <Route path="/login" component={Login} exact={true} />
    </Switch>
);

const jsx = (
<Provider store={store}>
    <MuiThemeProvider> 
       <BrowserRouter>
         <div>
           <AppRouter />
           <Route component={App} />
         </div>
       <BrowserRouter>
    </MuiThemeProvider>
</Provider>
);

Answer 2

为了在道具中包含history ，可以使用withRouter 。
如下更新App.js文件：

import { withRouter } from 'react-router'

...

export default withRouter(connect(mapStateToProps)(App));

Answer 3

请使用https://github.com/ReactTraining/react-router/blob/master/packages/react-router/docs/api/Redirect.md ，您可以仅在App.js渲染组件

 componentWillUpdate(nextProps, nextState) {

if (nextProps.store.user.email === null || nextProps.store.user.email 
== undefined) {
  return <Redirect to="/login" />
}