1、Router

1.1 路由

1.2 认识React-Router

npm install react-router-dom

1.3 Link和NavLink

1.4 Navigate

import React, { PureComponent } from "react";
import { Navigate } from "react-router-dom";

export class Login extends PureComponent {
  constructor(props) {
    super(props);

    this.state = {
      isLogin: false,
    };
  }

  login() {
    this.setState({ isLogin: true });
  }

  render() {
    const { isLogin } = this.state;

    return (
      <div>
        <h1>Login Page</h1>
        {/* 如果没有登录的话显示登录按钮
            已经登录则跳转到/home页面 */}
        {!isLogin ? (
          <button onClick={(e) => this.login()}>登录</button>
        ) : (
          <Navigate to="/home" />
        )}
      </div>
    );
  }
}

export default Login;

1.5 Not Found页面配置

      <Routes>
         <Route path="*" element={<NotFound />} />
      </Routes>

1.6 路由的嵌套

1.7 手动路由的跳转

1.7.1 在函数式组件中使用hook

1.7.2 在类组件中封装高阶组件

1.8 动态路由传递参数

• hoc

import {
  useLocation,
  useNavigate,
  useParams,
  useSearchParams,
} from "react-router-dom";

const withRouter = (WrapperComponent) => {
  return (props) => {
    // 1.导航
    const navigate = useNavigate();

    // 2.动态路由的参数 ：/detail/:id
    const params = useParams();

    // 3.查询字符串的参数: /user?name=why&age=18
    const location = useLocation();

    const [searchParams] = useSearchParams();
    const query = Object.fromEntries(searchParams);

    // Object.fromEntries([
    //   ["a", "b"],
    //   ["c", "d"],
    // ]);
    //Object{a:"b", c:"d"}

    const router = { navigate, params, location, query };

    return <WrapperComponent {...props} router={router} />;
  };
};

export default withRouter;

import React, { PureComponent } from 'react'
import { withRouter } from '../hoc'

export class Detail extends PureComponent {
  render() {
    const { router } = this.props
    const { params } = router

    return (
      <div>
        <h1>Detail Page</h1>
        <h2>id: {params.id}</h2>
      </div>
    )
  }
}

export default withRouter(Detail)

import React, { PureComponent } from 'react'
import { withRouter } from '../hoc'

export class User extends PureComponent {
  render() {
    const { router } = this.props
    const { query } = router

    return (
      <div>
        <h1>User: {query.name}-{query.age}</h1>
      </div>
    )
  }
}

export default withRouter(User)

1.9 路由的配置文件以及懒加载

import Home from "../pages/Home";
import HomeRecommend from "../pages/HomeRecommend";
import HomeRanking from "../pages/HomeRanking";
import HomeSongMenu from "../pages/HomeSongMenu";
// import About from "../pages/About"
// import Login from "../pages/Login"
import Category from "../pages/Category";
import Order from "../pages/Order";
import NotFound from "../pages/NotFound";
import Detail from "../pages/Detail";
import User from "../pages/User";
import { Navigate } from "react-router-dom";
import React from "react";

// import 返回的是一个Promise
const About = React.lazy(() => import("../pages/About"));
const Login = React.lazy(() => import("../pages/Login"));

const routes = [
  {
    path: "/",
    // 重定向
    element: <Navigate to="/home" />,
  },
  {
    path: "/home",
    element: <Home />,
    children: [
      // 子路由
      {
        path: "/home",
        element: <Navigate to="/home/recommend" />,
      },
      {
        path: "/home/recommend",
        element: <HomeRecommend />,
      },
      {
        path: "/home/ranking",
        element: <HomeRanking />,
      },
      {
        path: "/home/songmenu",
        element: <HomeSongMenu />,
      },
    ],
  },
  {
    path: "/about",
    element: <About />,
  },
  {
    path: "/login",
    element: <Login />,
  },
  {
    path: "/category",
    element: <Category />,
  },
  {
    path: "/order",
    element: <Order />,
  },
  {
    path: "/detail/:id",
    element: <Detail />,
  },
  {
    path: "/user",
    element: <User />,
  },
  {
    path: "*",
    element: <NotFound />,
  },
];

export default routes;

// import { StrictMode } from "react"
import ReactDOM from "react-dom/client";
import App from "./App";
import { HashRouter } from "react-router-dom";
import { Suspense } from "react";

const root = ReactDOM.createRoot(document.querySelector("#root"));
root.render(
  // <StrictMode>
  <HashRouter>
    // 需要加上Suspense 如果数据js 和 css文件还没请求回来就显示这里的内容
    <Suspense fallback={<h3>Loading...</h3>}>
      <App />
    </Suspense>
  </HashRouter>
  // </StrictMode>
);