vue项目实现路由按需加载(路由懒加载)的3种方式

1.vue异步组件
2.es提案的import()
3.webpack的require,ensur

*1.vue异步组件技术 ==== 异步加载
vue-router配置路由 , 使用vue的异步组件技术 , 可以实现按需加载 .
但是,这种情况下一个组件生成一个js文件*

/* vue异步组件技术 */
{path: '/home',name: 'home',component: resolve => require(['@/components/home'],resolve)
},{path: '/index',name: 'Index',component: resolve => require(['@/components/index'],resolve)
},{path: '/about',name: 'about',component: resolve => require(['@/components/about'],resolve)
} 

2.组件懒加载方案二 路由懒加载(使用import)

// 下面2行代码，没有指定webpackChunkName，每个组件打包成一个js文件。
/* const Home = () => import('@/components/home')
const Index = () => import('@/components/index')
const About = () => import('@/components/about') */
// 下面2行代码，指定了相同的webpackChunkName，会合并打包成一个js文件。 把组件按组分块
const Home =  () => import(/* webpackChunkName: 'ImportFuncDemo' */ '@/components/home')
const Index = () => import(/* webpackChunkName: 'ImportFuncDemo' */ '@/components/index')
const About = () => import(/* webpackChunkName: 'ImportFuncDemo' */ '@/components/about')

{path: '/about',component: About
}, {path: '/index',component: Index
}, {path: '/home',component: Home
}

3.webpack提供的require.ensure()
vue-router配置路由，使用webpack的require.ensure技术，也可以实现按需加载。
这种情况下，多个路由指定相同的chunkName，会合并打包成一个js文件。

/* 组件懒加载方案三: webpack提供的require.ensure() */
{path: '/home',name: 'home',component: r => require.ensure([], () => r(require('@/components/home')), 'demo')
}, {path: '/index',name: 'Index',component: r => require.ensure([], () => r(require('@/components/index')), 'demo')
}, {path: '/about',name: 'about',component: r => require.ensure([], () => r(require('@/components/about')), 'demo-01')
}