vant 按需引入

1.第一种方式

import {Search, Tab, Tabs, Button, List, Toast} from 'vant'
export default {
  components: {
    'van-search': Search,
    'van-tabs': Tabs,
    'van-tab': Tab,
    'van-button': Button,
    'van-list': List,
    Toast
  },

2.第二种方式

import Vue from 'vue'
import {Search, Tab, Tabs, Button, List, Toast} from 'vant'
Vue.use(Search)
Vue.use(Tab)
Vue.use(Tabs)
Vue.use(Button)
Vue.use(List)
Vue.use(Toast)