React 路由：URL 正在更改，但页面未加载

Question

在 React(v16.13.1) 中，网址正在更改，但页面未加载。

我在堆栈中发现了类似的问题 ReactJS - React Router not changing component but url is changing 和 React Router URL Change but Not Component，我尝试了不同的方式，但没有一个对我有帮助。

这可能是一个小错误，请帮助纠正这个问题。

我的代码如下：

App.js 文件

import React, { Component } from "react";
import { BrowserRouter as Router, Route,Switch,Redirect } from "react-router-dom";
import TopNav from "./components/Navbar/TopNav";
import SideNav from "./components/Navbar/SideNav";
import Dashboard from "./components/Dashboard";
import Analytics from "./components/Analytics";
import ToDo from "./components/ToDo";

class App extends React.Component {
  render() {
    return (
      <div>
        <TopNav />
        <SideNav />
        <Router>
          <Switch>
            <Route exact path="/">
              <Dashboard />
            </Route>
            <Route exact path="/analytics">
              <Analytics />
            </Route>
            {/* <Route exact path="/analytics" component={Analytics}></Route> */}
            <Route exact path="/todo">
              <ToDo />
            </Route>
            <Redirect to="/"></Redirect>
          </Switch>
        </Router>
      </div>
    );
  }
}
export default App;

SideNav.js 页面如下：

import React from "react";
import { BrowserRouter as Router, Link } from "react-router-dom";

class SideNav extends React.Component {
  render() {
    return (
      <div className="sidebar-wrapper">
        <div className="sidebar-container">
          <Router>
            <ul className="sidebar-menu">
              <li className="active">
                <i className="fa fa-cubes"></i>
                <Link className="link" to="/">
                  Dashboard
                </Link>
              </li>
              <li>
                <i className="fa fa-pie-chart"></i>
                <Link className="link" to="/analytics">
                  Analytics
                </Link>
              </li>
              <li>
                <i className="fa fa-medkit"></i>
                <Link className="link" to="/todo">
                  What to do?
                </Link>
              </li>
            </ul>
          </Router>
        </div>
      </div>
    );
  }
}
export default SideNav;

提前致谢！

Answer 1

您只需要在应用的顶层有一个<Router>。

您已经在 App 组件中使用了 <Router>。

将SideNav 组件包裹在Router 中，并删除SideNav 中使用的Router。

import React, { Component } from "react";
import {
  BrowserRouter as Router,
  Route,
  Switch,
  Redirect,
  Link
} from "react-router-dom";

class SideNav extends Component {
  render() {
    return (
      <div className="sidebar-wrapper">
        <div className="sidebar-container">
          {/* <Router> */}
          <ul className="sidebar-menu">
            <li className="active">
              <i className="fa fa-cubes" />
              <Link className="link" to="/">
                Dashboard
              </Link>
            </li>
            <li>
              <i className="fa fa-pie-chart" />
              <Link className="link" to="/analytics">
                Analytics
              </Link>
            </li>
            <li>
              <i className="fa fa-medkit" />
              <Link className="link" to="/todo">
                What to do?
              </Link>
            </li>
          </ul>
          {/* </Router> */}
        </div>
      </div>
    );
  }
}

class App extends Component {
  render() {
    return (
      <div>
        <Router>
          <SideNav />
          <Switch>
            <Route exact path="/">
              <div>/</div>
            </Route>
            <Route exact path="/analytics">
              <div>ana</div>
            </Route>
            <Route exact path="/todo">
              <div>todo</div>
            </Route>
            <Redirect to="/" />
          </Switch>
        </Router>
      </div>
    );
  }
}
export default App;

Answer 2

您的<SideNav /> 和主要内容在单独的<Router />s 中。他们看不见对方，也不能一起工作。
想象一下，就像两个相互独立导航的 iframe，只是没有实际的 iframe。

需要路由器的所有内容，基本上是整个应用程序，都需要在单个 <Router /> 中。

import React, { Component } from "react";
import { BrowserRouter as Router, Route, Switch, Redirect } from "react-router-dom";
import TopNav from "./components/Navbar/TopNav";
import SideNav from "./components/Navbar/SideNav";
import Dashboard from "./components/Dashboard";
import Analytics from "./components/Analytics";
import ToDo from "./components/ToDo";

class App extends React.Component {
  render() {
    return (
      <Router>
        <TopNav />
        <SideNav />
        <Switch>
          <Route exact path="/">
            <Dashboard />
          </Route>
          <Route exact path="/analytics">
            <Analytics />
          </Route>
          {/* <Route exact path="/analytics" component={Analytics}></Route> */}
          <Route exact path="/todo">
            <ToDo />
          </Route>
          <Redirect to="/"></Redirect>
        </Switch>
      </Router>
    );
  }
}
export default App;

SideNav.js

import React from "react";
import { BrowserRouter as Router, Link } from "react-router-dom";

class SideNav extends React.Component {
  render() {
    return (
      <div className="sidebar-wrapper">
        <div className="sidebar-container">
          <ul className="sidebar-menu">
            <li className="active">
              <i className="fa fa-cubes"></i>
              <Link className="link" to="/">
                Dashboard
              </Link>
            </li>
            <li>
              <i className="fa fa-pie-chart"></i>
              <Link className="link" to="/analytics">
                Analytics
              </Link>
            </li>
            <li>
              <i className="fa fa-medkit"></i>
              <Link className="link" to="/todo">
                What to do?
                </Link>
            </li>
          </ul>
        </div>
      </div>
    );
  }
}

这同样适用于TopNav.js。