背景

随着项目越来越大，打包后的包体积也越来越大，严重影响了首屏加载速度，需要对路由和组件做懒加载处理

主要用到了react中的lazy和Suspense。

废话不多说，直接上干货

路由懒加载

核心代码

import React, { lazy, Suspense } from "react";
const loading = () => <h3>loading....</h3>;
const Caidan1 = lazy(() => import("@/pages/mud1/caidan1"));const meunRoutes = [{name: "模块1",path: "/m1",icon: <AppstoreOutlined />,children: [{name: "gltf模型",path: "/m1/caidan12",icon: <AppstoreOutlined />,element: (<Suspense fallback={loading()}><Caidan1 /></Suspense>),},// 。。。。

配合路由表的完整例子

// 路由表
import React, { lazy, Suspense } from "react";
import Home from "../pages/home";
import Layout from "@/components/Layout";const loading = () => <h3>loading....</h3>;const Caidan1 = lazy(() => import("@/pages/mud1/caidan1"));
const Caidan2 = lazy(() => import("@/pages/mud1/caidan2"));
// 404页面
const NotFound = () => <h1>**** 404 ****</h1>;const meunRoutes = [{name: "模块1",path: "/m1",icon: <AppstoreOutlined />,children: [{name: "gltf模型",path: "/m1/caidan12",icon: <AppstoreOutlined />,element: (<Suspense fallback={loading()}><Caidan1 /></Suspense>),},{name: "模型动画",path: "/m1/caidan13",icon: <AppstoreOutlined />,element: (<Suspense fallback={loading()}><Caidan2 /></Suspense>),},],},
];// 配置路由表
const routes = [{path: "/",element: <Navigate to="/home" />,},{path: "/home",element: <Home />,},{path: "/",element: <Layout />,children: handleMenuRoutes(meunRoutes),},{ path: "*", element: <NotFound /> },
];// 处理menu routes
function handleMenuRoutes(arr) {let res = [];arr.forEach((item) => {if (item.children && item.children.length > 0) {item.children.forEach((yitem) => {let obj = {path: yitem.path,element: yitem.element,};res.push(obj);});}});return res;
}const AppRouter = () => useRoutes([...routes]);
export { AppRouter, meunRoutes };

组件懒加载

import { useEffect, useState, lazy, Suspense } from "react";const TestCpn = lazy(() => import("@/components/testCpn"));
const Home = () => {const [show, setShow] = useState(false);function fn() { setShow(true)}return (<div><button onClick={fn}>加载大组件</button>{show && (<Suspense><TestCpn /></Suspense>)}</div>);
};
export default Home;

效果
组件加载前

组件懒加载后

这样就会大大加快首屏加载速度