Element提供了upload上传组件，可以查看官网组件的详细介绍；查看upload组件的上传源码upload/ajax，使用的是XHR对象上传文件。在项目实践中，发现该上传方法上传大文件时会出现问题，所以决定使用阿里云对象存储服务（Object Storage Service，简称OSS），详细介绍可以查看官网，本文主要讲解的是OSS上传文件的前端，后台开发请查看官网介绍，讲解了前端如何进行上传。
1、使用npm安装SDK的开发包：
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' });
最新版的没有了Wrapper构造函数，直接配置
let oss = require('ali-oss'); var client = oss({ accessKeyId: 'your access key', accessKeySecret: 'your access secret', bucket: 'your bucket name', region: 'oss-cn-hangzhou' });
3、上传文件
OSS上传文件分为上传Buffer内容、上传blob数据、分片上传，此处展示
let result = await client.multipartUpload('object-key', 'local-file', { progress: async function (p) { console.log('Progress: ' + p); } });
js调用OSS上传文件已经没有问题，但是我们需要实现公用上传组件，Element UI已经实现了Upload上传组件，包括上传进度、异常处理、拖拽等；那我们还有必要重新开发一个像Upload一样的组件吗？通过查看Upload组件的API发现有一个http-request属性，http-request覆盖默认的上传行为，可以自定义上传的实现；看到这个我就省了很多事，直接用OSS上传覆盖XHR上传。代码如下：
<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></i> <div>将文件拖到此处，或<em>点击上传</em></div> <div slot="tip">上传文件大小不能超过 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 覆盖默认的上传行为，实现自定义上传] * @author shanshuizinong * @param {object} option [上传选项] * @return {null} [没有返回] */ async fnUploadRequest (option) { try { let vm = this vm.disabled = true // 获取OSS配置信息 let uploadFileApi = new UploadFileApi() let ret = await uploadFileApi.fileOssParams() if (!(ret.data && ret.data.code === '0' && ret.data.data)) { throw new Error('获取OSS参数失败') } 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}` // 分片上传文件 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('上传失败') } } catch (error) { console.error(error) this.disabled = false option.onError('上传失败') this.$error(error.message) } }, /** * @description [fnUploadSuccess 文件上传成功的函数] * @author shanshuizinong * @return {null} [没有返回] */ async fnUploadSuccess () { // TODO } } } </script>
查看upload源码upload.vue知道httpRequest会有一个文件上传的option选项作为参数，upload/ajax源码中上传进度、上传成功、上传失败都是通过option调用其方法进行触发。