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【前端】【React】第四章：深入理解 React Router 及前端路由管理

news 来源：原创 2025/6/21 11:48:30

十一、React Router 及前端路由管理

React 是一个单页面应用（SPA）框架，通常使用 React Router 进行路由管理。React Router 提供 客户端路由，避免页面刷新，提高用户体验。

（一）React Router 基本概念

React Router 采用 基于组件的路由，核心概念包括：

术语	作用
`BrowserRouter`	使应用支持 HTML5 History API 的路由
`Routes`	用于包裹所有 `Route` 组件
`Route`	定义 URL 与组件的映射关系
`Link` / `NavLink`	生成前端导航链接
`useNavigate`	编程式导航，替代 `history.push`
`useParams`	获取 URL 动态参数
`useLocation`	获取当前 URL 信息

（二）安装 React Router

npm install react-router-dom

（三）基本路由配置

1. 创建路由

import { BrowserRouter, Routes, Route } from "react-router-dom";
import Home from "./Home";
import About from "./About";

function App() {
  return (
    <BrowserRouter>
      <Routes>
        <Route path="/" element={<Home />} />
        <Route path="/about" element={<About />} />
      </Routes>
    </BrowserRouter>
  );
}

export default App;

2. 创建 `Home` 和 `About` 组件

function Home() {
  return <h1>首页</h1>;
}

function About() {
  return <h1>关于我们</h1>;
}

（四）导航链接 `Link` 和 `NavLink`

1. 使用 `Link` 进行跳转

import { Link } from "react-router-dom";

function Navbar() {
  return (
    <nav>
      <Link to="/">首页</Link>
      <Link to="/about">关于我们</Link>
    </nav>
  );
}

2. `NavLink`（添加选中状态）

import { NavLink } from "react-router-dom";

function Navbar() {
  return (
    <nav>
      <NavLink to="/" style={({ isActive }) => ({ color: isActive ? "red" : "black" })}>
        首页
      </NavLink>
      <NavLink to="/about">关于我们</NavLink>
    </nav>
  );
}

（五）动态路由与参数 `useParams`

1. 定义动态路由

<Routes>
  <Route path="/user/:id" element={<User />} />
</Routes>

2. 获取路由参数

import { useParams } from "react-router-dom";

function User() {
  const { id } = useParams();
  return <h1>用户 ID: {id}</h1>;
}

（六）编程式导航 `useNavigate`

1. 跳转到指定页面

import { useNavigate } from "react-router-dom";

function Home() {
  const navigate = useNavigate();

  return (
    <div>
      <h1>首页</h1>
      <button onClick={() => navigate("/about")}>跳转到关于页</button>
    </div>
  );
}

2. 传递参数

navigate("/user/123");

（七）获取当前路由 `useLocation`

import { useLocation } from "react-router-dom";

function CurrentRoute() {
  const location = useLocation();
  return <h1>当前路径: {location.pathname}</h1>;
}

（八）嵌套路由（子路由）

1. 定义子路由

<Routes>
  <Route path="/dashboard" element={<Dashboard />}>
    <Route path="profile" element={<Profile />} />
    <Route path="settings" element={<Settings />} />
  </Route>
</Routes>

2. 在 `Dashboard` 组件中渲染子组件

import { Outlet } from "react-router-dom";

function Dashboard() {
  return (
    <div>
      <h1>仪表盘</h1>
      <Outlet />
    </div>
  );
}

（九）路由重定向

1. 使用 `Navigate` 组件

import { Navigate } from "react-router-dom";

function NotFound() {
  return <Navigate to="/" />;
}

（十）路由守卫（权限控制）

1. 创建 `ProtectedRoute` 组件

import { Navigate } from "react-router-dom";

function ProtectedRoute({ isAuth, children }) {
  return isAuth ? children : <Navigate to="/login" />;
}

2. 使用路由守卫

<Route path="/dashboard" element={<ProtectedRoute isAuth={isLoggedIn}><Dashboard /></ProtectedRoute>} />

十二、总结

1. React Router 核心概念

术语	作用
`Routes` / `Route`	定义路由
`Link` / `NavLink`	导航链接
`useNavigate`	编程式跳转
`useParams`	获取动态参数
`useLocation`	获取当前 URL
`Navigate`	进行路由重定向
`Outlet`	处理嵌套路由

2. 路由功能

基本路由：<Route path="/" element={<Home />} />
动态路由：<Route path="/user/:id" element={<User />} />
导航链接：<Link to="/about">关于我们</Link>
编程式导航：navigate("/dashboard")
嵌套路由：<Outlet />
路由重定向：<Navigate to="/" />
路由守卫：封装 <ProtectedRoute> 组件

在大型 React 应用中，单独维护路由表 是一种更好的实践，可以提高可读性、可维护性和复用性。通常，开发者会在 routes.js 或 router/index.js 文件中集中管理路由。

（一）使用独立路由表

1. 创建 `routes.js`

// routes.js
import Home from "./pages/Home";
import About from "./pages/About";
import Dashboard from "./pages/Dashboard";
import Profile from "./pages/Profile";
import Settings from "./pages/Settings";
import NotFound from "./pages/NotFound";

const routes = [
  { path: "/", element: <Home /> },
  { path: "/about", element: <About /> },
  {
    path: "/dashboard",
    element: <Dashboard />,
    children: [
      { path: "profile", element: <Profile /> },
      { path: "settings", element: <Settings /> },
    ],
  },
  { path: "*", element: <NotFound /> },
];

export default routes;

2. 在 `App.js` 里引入并渲染

// App.js
import { BrowserRouter, Routes, Route } from "react-router-dom";
import routes from "./routes";

function App() {
  return (
    <BrowserRouter>
      <Routes>
        {routes.map(({ path, element, children }) => (
          <Route key={path} path={path} element={element}>
            {children &&
              children.map((child) => (
                <Route key={child.path} path={child.path} element={child.element} />
              ))}
          </Route>
        ))}
      </Routes>
    </BrowserRouter>
  );
}

export default App;

（二）改进：使用 `lazy` 和 `Suspense` 进行按需加载

当页面较多时，可以使用 React.lazy 进行 按需加载（懒加载），减少首屏加载时间。

1. 修改 `routes.js`

import { lazy } from "react";

const Home = lazy(() => import("./pages/Home"));
const About = lazy(() => import("./pages/About"));
const Dashboard = lazy(() => import("./pages/Dashboard"));
const Profile = lazy(() => import("./pages/Profile"));
const Settings = lazy(() => import("./pages/Settings"));
const NotFound = lazy(() => import("./pages/NotFound"));

const routes = [
  { path: "/", element: <Home /> },
  { path: "/about", element: <About /> },
  {
    path: "/dashboard",
    element: <Dashboard />,
    children: [
      { path: "profile", element: <Profile /> },
      { path: "settings", element: <Settings /> },
    ],
  },
  { path: "*", element: <NotFound /> },
];

export default routes;

2. 在 `App.js` 里添加 `Suspense`

import { BrowserRouter, Routes, Route } from "react-router-dom";
import { Suspense } from "react";
import routes from "./routes";

function App() {
  return (
    <BrowserRouter>
      <Suspense fallback={<div>加载中...</div>}>
        <Routes>
          {routes.map(({ path, element, children }) => (
            <Route key={path} path={path} element={element}>
              {children &&
                children.map((child) => (
                  <Route key={child.path} path={child.path} element={child.element} />
                ))}
            </Route>
          ))}
        </Routes>
      </Suspense>
    </BrowserRouter>
  );
}

export default App;

（三）结合路由守卫

在 routes.js 里可以添加 权限控制，通过 meta.auth 判断是否需要登录：

1. 修改 `routes.js`

import { lazy } from "react";
import ProtectedRoute from "./components/ProtectedRoute";

const Home = lazy(() => import("./pages/Home"));
const About = lazy(() => import("./pages/About"));
const Dashboard = lazy(() => import("./pages/Dashboard"));
const Login = lazy(() => import("./pages/Login"));

const routes = [
  { path: "/", element: <Home /> },
  { path: "/about", element: <About /> },
  {
    path: "/dashboard",
    element: <ProtectedRoute><Dashboard /></ProtectedRoute>,
    meta: { auth: true }, // 需要登录
  },
  { path: "/login", element: <Login /> },
];

export default routes;

2. 创建 `ProtectedRoute.js`

import { Navigate } from "react-router-dom";

function ProtectedRoute({ children }) {
  const isLoggedIn = localStorage.getItem("token"); // 模拟鉴权
  return isLoggedIn ? children : <Navigate to="/login" />;
}

export default ProtectedRoute;