uniapp如何引入vant ui组件？

1、新建一个uniapp项目，选择Vue2，不勾选unilcloud

2、右键项目名，选择菜单在命令行打开

3、输入 npm i vant@latest-v2

4、main.js改成这样

import App from './App'

// #ifndef VUE3
import Vue from 'vue'
import Vant from "vant";
import 'vant/lib/index.less'
Vue.use(Vant)
import './uni.promisify.adaptor'
Vue.config.productionTip = false
App.mpType = 'app'
const app = new Vue({
  ...App
})
app.$mount()
// #endif

// #ifdef VUE3
import { createSSRApp } from 'vue'
export function createApp() {
  const app = createSSRApp(App)
  return {
    app
  }
}
// #endif

chainWebpack:(config) => {
    config.module 
      .rule("mjs$")
      .test(/\.mjs$/)
      .include.add(/node_modules/)
      .end()
      .type("javascript/auto");
  }

<template>

	<view class="content">

		<van-swipe class="my-swipe" :autoplay="3000" indicator-color="white">
			<van-swipe-item>1</van-swipe-item>
			<van-swipe-item>2</van-swipe-item>
			<van-swipe-item>3</van-swipe-item>
			<van-swipe-item>4</van-swipe-item>
		</van-swipe>
		<van-grid>
			<van-grid-item icon="photo-o" text="文字" />
			<van-grid-item icon="setting-o" text="文字" />
			<van-grid-item icon="home-o" text="文字" />
			<van-grid-item icon="video-o" text="文字" />
			<van-grid-item icon="photo-o" text="文字" />
			<van-grid-item icon="setting-o" text="文字" />
			<van-grid-item icon="home-o" text="文字" />
			<van-grid-item icon="video-o" text="文字" />
		</van-grid>

		<van-card num="2" price="2.00" desc="描述信息" title="商品标题"
			thumb="https://repo.bfw.wiki/bfwrepo/image/5ff8f9d574eb5.png" />
		<van-card
		  num="2"
		  price="2.00"
		  desc="描述信息"
		  title="商品标题"
		  thumb="https://img01.yzcdn.cn/vant/ipad.jpeg"
		>
		  <template #tags>
		    <van-tag plain type="danger">标签</van-tag>
		    <van-tag plain type="danger">标签</van-tag>
		  </template>
		  <template #footer>
		    <van-button size="mini">按钮</van-button>
		    <van-button size="mini">按钮</van-button>
		  </template>
		</van-card>
		<van-card
  num="2"
  price="2.00"
  desc="描述信息"
  title="商品标题"
  thumb="https://img01.yzcdn.cn/vant/ipad.jpeg"
>
  <template #tags>
    <van-tag plain type="danger">标签</van-tag>
    <van-tag plain type="danger">标签</van-tag>
  </template>
  <template #footer>
    <van-button size="mini">按钮</van-button>
    <van-button size="mini">按钮</van-button>
  </template>
</van-card>


<van-sidebar v-model="activeKey">
  <van-sidebar-item title="标签名称" />
  <van-sidebar-item title="标签名称" />
  <van-sidebar-item title="标签名称" />
</van-sidebar>
		<van-form @submit="onSubmit">
			<van-field v-model="username" name="用户名" label="用户名" placeholder="用户名"
				:rules="[{ required: true, message: '请填写用户名' }]" />
			<van-field v-model="password" type="password" name="密码" label="密码" placeholder="密码"
				:rules="[{ required: true, message: '请填写密码' }]" />
			<div style="margin: 16px;">
				<van-button round block type="info" native-type="submit">提交</van-button>
			</div>
		</van-form>
		<van-popover>
			<template #reference>
				<van-button type="primary">浅色风格</van-button>
			</template>
		</van-popover>
		<van-tabbar>
			<van-tabbar-item icon="home-o">标签</van-tabbar-item>
			<van-tabbar-item icon="search">标签</van-tabbar-item>
			<van-tabbar-item icon="friends-o">标签</van-tabbar-item>
			<van-tabbar-item icon="setting-o">标签</van-tabbar-item>
		</van-tabbar>
		<!-- 		<van-submit-bar :price="3050" button-text="提交订单" @submit="onSubmit" /> -->
		<van-button type="info">style局部定制主题的信息按钮</van-button>

	</view>
	<!-- 组件文档地址 https://vant-contrib.gitee.io/vant/v2/#/zh-CN/popover -->
</template>

<script>
	export default {
		data() {
			return {
				title: 'Hello',
				username: '',
				password: '',
				show: true,
				sku: {
					// 数据结构见下方文档
				},
				goods: {
					// 数据结构见下方文档
				},
				messageConfig: {
					// 数据结构见下方文档
				},
			}
		},
		onLoad() {
			this.$toast('提示文案2');
			this.$dialog.alert({
				title: '标题',
				message: '弹窗内容',
				theme: 'round-button'
			});
		},
		methods: {
			onSubmit(values) {
				console.log('submit', values);
			},
		}
	}
</script>

<style>
	.my-swipe .van-swipe-item {
		color: #fff;
		font-size: 20px;
		line-height: 150px;
		text-align: center;
		background-color: #39a9ed;
	}
</style>

运行效果如下：