npm install vue-i18n

import VueI18n from 'vue-i18n'Vue.use(VueI18n)

const messages = {zh: {message: {hello: '好好学习，天天向上！'}},en: {message: {hello: 'good good study, day day up!'}}
}

const i18n = new VueI18n({locale: 'en', // 语言标识messages
})

const app = new Vue({router,i18n,...App
}).$mount('#app')

<div id="app"><h1 style="font-size: 16px; text-align: center;">{{ $t("message.hello") }}</h1></div>

const i18n = new VueI18n({locale: 'zh', // 语言标识messages
})

const i18n = new VueI18n({locale: 'en',  // 语言标识messages: {'zh': require('./common/lang/zh'),'en': require('./common/lang/en')}
})

// 注意：一定是 exports，不是 export，否则会报错，报错信息是下列的中的内容不是 string
module.exports = {message: {title: '运动品牌'},placeholder: {enter: '请输入您喜欢的品牌'},brands: {nike: '耐克',adi: '阿迪达斯',nb: '新百伦',ln: '李宁'}
}

module.exports = {message: {title: 'Sport Brands'},placeholder: {enter: 'Please type in your favorite brand'},brands: {nike: 'Nike',adi: 'Adidas',nb: 'New Banlance',ln: 'LI Ning'}
}

// HTML
<div id="app"><div style="margin: 20px;"><h1>{{$t("message.title")}}</h1><input style="width: 300px;" class="form-control" :placeholder="$t('placeholder.enter')"><ul><li v-for="brand in brands">{{brand}}</li></ul></div>
</div>// JS
data () {return {brands: [this.$t('brands.nike'), this.$t('brands.adi'), this.$t('brands.nb'), this.$t('brands.ln')]}},

function getCookie(name,defaultValue) {var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");if (arr = document.cookie.match(reg))return unescape(arr[2]);elsereturn defaultValue;
}export {getCookie
}

const i18n = new VueI18n({locale: getCookie('PLAY_LANG','zh'),    // 语言标识messages: {'zh': require('./common/lang/zh'),'en': require('./common/lang/en')}
})

// template
<h2>{{$t('test')}}</h2>
<button type="button" class="btn btn-success" @click="changeLocale">中文/EN</button>        

// js方法
changeLocale () {this.$confirm(this.$t('layer.toggle'), this.$t('layer.tips'), {confirmButtonText: this.$t('button.ok'),cancelButtonText: this.$t('button.cancel'),type: 'warning'}).then(() => {let locale = this.$i18n.localelocale === 'zh' ? this.$i18n.locale = 'en' : this.$i18n.locale = 'zh'}).catch(() => {this.$message({type: 'info',})      })
},

const i18n = new VueI18n({locale: localStorage.getItem('locale') || 'zh',messages
})

<div class="lang"><el-dropdown><i class="iconfont icon-language4"></i><el-dropdown-menu slot="dropdown"><el-dropdown-item @click.native="toggleLang('zh')" :disabled="$i18n.locale == 'zh'">中文</el-dropdown-item><el-dropdown-item @click.native="toggleLang('en')" :disabled="$i18n.locale == 'en'">English</el-dropdown-item></el-dropdown-menu></el-dropdown></div>

toggleLang(lang) {if(lang == 'zh'){localStorage.setItem('locale', 'zh')this.$i18n.locale = localStorage.getItem('locale')this.$message({message: '切换为中文！',type: 'success'})} else if (lang == 'en') {localStorage.setItem('locale', 'en')this.$i18n.locale = localStorage.getItem('locale')this.$message({message: 'Switch to English!',type: 'success'})
}

i18n.jsimport Vue from 'vue'
import VueI18n from 'vue-i18n'
import locale from 'element-ui/lib/locale';
import zh from './langs/zh'
import en from './langs/en'
import enLocale from 'element-ui/lib/locale/lang/en'
import zhLocale from 'element-ui/lib/locale/lang/zh-CN'Vue.use(VueI18n)const messages = {en: Object.assign(en, enLocale),zh: Object.assign(zh, zhLocale)
}console.log(messages.zh)const i18n = new VueI18n({locale: localStorage.getItem('locale') || 'zh',messages
})locale.i18n((key, value) => i18n.t(key, value)) //为了实现element插件的多语言切换export default i18n

import i18n from './i18n/i18n'           // 1行window.app = new Vue({el: '#app',router,store,i18n,                                 // 2行components: { App },template: '<App/>'
})