檔案目錄：

i18n.js:

import Vue from 'vue'
import VueI18n from 'vue-i18n'
import en from './lang/en'
import cn from './lang/cn'
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: {
    ...en,
    ...enLocale
  },
  zh: {
    ...cn,
    ...zhLocale 
 
// 或者用 Object.assign({ message: '你好' }, zhLocale)
  }
}

const i18n = new VueI18n({
  locale: 'en', // 設定預設語言
  messages
})

export default i18n

cn.js:

const cn = {
  message: {
    i1: '歡迎來到我的專案',
  },
}


export default cn

en.js:

const en = {
  message: {
    i1: 'Welcome to my project',
  },
}


export 
 
default en;

main.js:

import i18n from './components/i18n/i18n.js';

Vue.use(ElementUI,{
  i18n: (key, value) => i18n.t(key, value)
});

new Vue({
  el: '#app',
  router,
  store,
  i18n,
  components: { App },
  template: '<App/>'
})

使用：

<template>
  <div class="hello">
    <
 
el-button type="primary" @click="switchChinese()">切換中文</el-button>
    <el-button type="primary" @click="switchEnlish()">切換英文</el-button>
    <p>{{ $t("message.i1") }}</p>
    <el-date-picker
      v-model="value1"
      type="date"
      placeholder="選擇日期">
    </el-date-picker>
  </div>
</template>

<script>
export default {
  name: "HelloWorld",
  data() {
    return {value1: '',};
  },
  methods: {
    switchChinese() {
      this.$i18n.locale = "zh";
    },
    switchEnlish() {
      this.$i18n.locale = "en";
    },
  },
};
</script>

效果：