Element提供了upload上傳元件，可以檢視官網upload元件的詳細介紹；檢視upload元件的上傳原始碼upload/ajax，使用的是XHR物件上傳檔案。在專案實踐中，發現該上傳方法上傳大檔案時會出現問題，所以決定使用阿里雲物件儲存服務（Object Storage Service，簡稱OSS），OSS詳細介紹可以檢視官網，本文主要講解的是OSS上傳檔案的前端，後臺開發請檢視官網介紹，SDK Browser.js講解了前端如何進行上傳。

1、使用npm安裝SDK的開發包：

npm install ali-oss

2、OSS配置

let oss = require('ali-oss'
 
);
let client= new OSS.Wrapper({
  accessKeyId: 'your access key',
  accessKeySecret: 'your access secret',
  bucket: 'your bucket name',
  region: 'oss-cn-hangzhou'
});

3、上傳檔案
  OSS上傳檔案分為上傳Buffer內容、上傳blob資料、分片上傳，此處展示分片上傳

let result = await client.multipartUpload('object-key', 'local-file', {
    progress: async function
 
 (p) {
      console.log('Progress: ' + p);
    }
  });

  js呼叫OSS上傳檔案已經沒有問題，但是我們需要實現公用上傳元件，Element UI已經實現了Upload上傳元件，包括上傳進度、異常處理、拖拽等；那我們還有必要重新開發一個像Upload一樣的元件嗎？通過檢視Upload元件的API發現有一個http-request屬性，http-request覆蓋預設的上傳行為，可以自定義上傳的實現；看到這個我就省了很多事，直接用OSS上傳覆蓋XHR上傳。程式碼如下：

<template>
  <div>
    <el-upload
 
      :auto-upload="false"
      :action="uploadUrl"
      ref="upload"
      :before-upload="fnBeforeUpload"
      :on-success="fnUploadSuccess"
      :on-exceed="fnUploadExceed"
      :data="data_extra"
      :headers="uploadHeaders"
      :http-request="fnUploadRequest"
      drag
      :limit="files"
      :disabled="disabled"
      multiple>
      <i class="el-icon-upload"></i>
      <div class="el-upload__text">將檔案拖到此處，或<em>點選上傳</em></div>
      <div slot="tip" class="el-upload__tip">上傳檔案大小不能超過 1G</div>
    </el-upload>
  </div>
</template>
<script>
import UploadFileApi from '@/api/system/UploadFileApi'
import * as util from 'utils/common'
import OSS from 'ali-oss'
export default {
  name: 'fileUpload',
  props: {
    data_extra: {
      type: Object,
      required: true
    },
    accept: {
      type: Array,
      required: true
    }
  },
  data () {
    return {
      uploadUrl: '',
      uploadFileLength: 0,
      uploadFileSuccess: 0,
      uploadFileNames: [],
      uploadFileName: [],
      fileList: [],
      files: 10,
      uploadHeaders: {
        authorization: ''
      },
      disabled: false
    }
  },
  methods: {
    /**
     * @description [fnUploadRequest 覆蓋預設的上傳行為，實現自定義上傳]
     * @author   shanshuizinong
     * @param    {object}   option [上傳選項]
     * @return   {null}   [沒有返回]
     */
    async fnUploadRequest (option) {
      try {
        let vm = this
        vm.disabled = true
        // 獲取OSS配置資訊
        let uploadFileApi = new UploadFileApi()
        let ret = await uploadFileApi.fileOssParams()
        if (!(ret.data && ret.data.code === '0' && ret.data.data)) {
          throw new Error('獲取OSS引數失敗')
        }
        let ossData = JSON.parse(ret.data.data)
        let relativePath = ossData.relativePath
        let client = new OSS.Wrapper({
          policy: ossData.policy,
          accessKeyId: ossData.accessid,
          accessKeySecret: ossData.accesssecret,
          bucket: ossData.bucket,
          signature: ossData.signature
        })
        let file = option.file
        const point = file.name.lastIndexOf('.')
        let suffix = file.name.substr(point)
        let fileName = file.name.substr(0, point)
        let date = vm.$moment().format('YYYYMMDDHHmm')
        let fileNames = `${fileName}_${date}${suffix}`
        // 分片上傳檔案
        ret = await client.multipartUpload(relativePath + fileNames, file, {
          progress: async function (p) {
            let e = {}
            e.percent = p * 100
            option.onProgress(e)
          }
        })
        console.log(ret)
        if (ret.res.statusCode === 200) {
          option.onSuccess(ret)
          return ret
        } else {
          vm.disabled = false
          option.onError('上傳失敗')
        }
      } catch (error) {
        console.error(error)
        this.disabled = false
        option.onError('上傳失敗')
        this.$error(error.message)
      }
    },
    /**
     * @description [fnUploadSuccess 檔案上傳成功的函式]
     * @author   shanshuizinong
     * @return   {null}  [沒有返回]
     */
    async fnUploadSuccess () {
      // TODO
    }
  }
}
</script>

  檢視upload原始碼upload.vue知道httpRequest會有一個檔案上傳的option選項作為引數，upload/ajax原始碼中上傳進度、上傳成功、上傳失敗都是通過option呼叫其方法進行觸發。