vue下载文件时显示进度条

1.单个下载（开始是导出按钮下载显示进度条）

html

 <el-button @click.stop="exportReport(scope.row, scope.index)" v-if="!scope.row.schedule" icon="el-icon-download"size="small" type="text"style="color: #409eff">导出报告</el-button><el-progress style="width: 60px;display:inline-block;margin-left: 20px;" v-else :text-inside="true" :stroke-width="20" :percentage="scope.row.scheduleNumber" status="success" />

因为接口没有返回schedule和scheduleNumber数据只是前端需要用来判断显示按钮还是进度条的所以就手动给数组添加响应式数据

     this.data.map((item, index) => {this.$set(item, 'schedule', false);this.$set(item, 'scheduleNumber', 0);return item;});

js部分

  exportReport(row) {let data=this.visible?this.selectionList:this.data// 自己封装的方法downloadGet('/api/blade-robot/siteInfo/export-template','巡检报告', this.schedule, row).then(() => {data.forEach((x) => {if (x.id === row.id) {x.schedule = false}})})},schedule(progressEvent, row) {// 回调的progressEvent参数里有一个progressEvent.loaded和progressEvent.total两个参数，分别意思为已下载的文件大小和总文件大小// 因为total一直为0，经研究发现需要后端传给我ContentLength到response里这个值才会有值// 然而又发现后端使用的是minio这个文件服务器，所以这个文件大小太难获取了，所以我决定不改后端，直接写死了文件大小setTimeout(() => {let data=this.visible?this.selectionList:this.datadata.forEach((x) => {if (x.id === row.id) {x.schedule = truex.scheduleNumber = Math.round(progressEvent.loaded / 3715 * 100)if( x.schedule == true){setTimeout(() => {x.schedule = false}, 2000);}}})}, 2000);},

downloadGet方法

export const downloadGet = (url, filename, callback, callbackParameter)=> {return request({url:url, method: 'get',responseType: 'blob',timeout: 120000,// 下载的实时回调，axios里的onDownloadProgress: (a) => {if (callback) {callback(a, callbackParameter)}}}).then((r) => {// 下面的代码就是拿到字节流后转为文件的方法，想研究的可以自行百度const content = r.dataconst blob = new Blob([content],{type: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'})if ('download' in document.createElement('a')) {const elink = document.createElement('a')elink.download = filenameelink.style.display = 'none'elink.href = URL.createObjectURL(blob)document.body.appendChild(elink)elink.click()URL.revokeObjectURL(elink.href)document.body.removeChild(elink)}else if (typeof window.navigator.msSaveBlob !== 'undefined'){// IElet blob = new Blob([content], {type: 'application/force-download'});navigator.msSaveBlob(blob, filename)}else {// Firefoxvar file = new File([content], filename, {type: 'application/force-download'});window.open(URL.createObjectURL(file));}}).catch((r) => {console.error(r)})
}

以上就可以实现每行下载时候去显示进度条了

2.批量下载弹框

弹框html

<el-dialog title="批量导出巡检报告" @close="toClose":close-on-click-modal="false" :visible="visible" lock-scroll append-to-bodywidth="600px" :modal-append-to-body="false"><el-table :data="selectionList" border style="width: 100%"><el-table-column type="index"label="序号" width="50"></el-table-column><el-table-column prop="id" label="文件名称"><template slot-scope="scope"><span>{{scope.row.id}}巡检报告</span></template></el-table-column><el-table-column prop="scheduleNumber" label="下载进度"><template slot-scope="scope"><el-progress :percentage="scope.row.scheduleNumber"  :text-inside="true" :stroke-            width="20"  status="success"></el-progress></template></el-table-column></el-table>
</el-dialog>

    import { deepClone } from "@/util/util";//引入深拷贝方法//表格选中多个selectionChange(list) {this.selectionList = deepClone(list);},//点击批量下载方法handleDelete() {if (this.selectionList.length === 0) {this.$message.warning("请选择至少一条数据");return;}this.$confirm("确定将选择数据批量导出巡检报告?", {confirmButtonText: "确定",cancelButtonText: "取消",type: "warning"}).then(() => {this.$nextTick(() => {this.visible=truethis.selectionList.forEach(item=>{this.exportReport(item)})});}).catch(() => {});},//关闭弹框清空选中状态toClose(){this.visible=falsethis.onLoad(this.page);this.$refs.crud.toggleSelection();},

深拷贝方法（不使用深拷贝的话弹框和表格进度条会冲突！！！！！）

/*** 对象深拷贝*/
export const deepClone = data => {var type = getObjType(data)var objif (type === 'array') {obj = []} else if (type === 'object') {obj = {}} else {//不再具有下一层次return data}if (type === 'array') {for (var i = 0, len = data.length; i < len; i++) {obj.push(deepClone(data[i]))}} else if (type === 'object') {for (var key in data) {obj[key] = deepClone(data[key])}}return obj
}

最后就是设置导出文件的类型在上文封装下载方法中 type设置的

const blob = new Blob([content],{type: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'})

关于 Blob 的 content-type 的部分媒体类型可以参照下面！！！！！

".*"="application/octet-stream"
".001"="application/x-001"
".301"="application/x-301"
".323"="text/h323"
".906"="application/x-906"
".907"="drawing/907"
".a11"="application/x-a11"
".acp"="audio/x-mei-aac"
".ai"="application/postscript"
".aif"="audio/aiff"
".aifc"="audio/aiff"
".aiff"="audio/aiff"
".anv"="application/x-anv"
".asa"="text/asa"
".asf"="video/x-ms-asf"
".asp"="text/asp"
".asx"="video/x-ms-asf"
".au"="audio/basic"
".avi"="video/avi"
".awf"="application/vnd.adobe.workflow"
".biz"="text/xml"
".bmp"="application/x-bmp"
".bot"="application/x-bot"
".c4t"="application/x-c4t"
".c90"="application/x-c90"
".cal"="application/x-cals"
".cat"="application/vnd.ms-pki.seccat"
".cdf"="application/x-netcdf"
".cdr"="application/x-cdr"
".cel"="application/x-cel"
".cer"="application/x-x509-ca-cert"
".cg4"="application/x-g4"
".cgm"="application/x-cgm"
".cit"="application/x-cit"".doc"="application/msword"
".docx"="application/vnd.openxmlformats-officedocument.wordprocessingml.document"
".rtf"="application/rtf"
".xls"="application/vnd.ms-excel application/x-excel"
".xlsx"="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
".ppt"="application/vnd.ms-powerpoint"
".pptx"="application/vnd.openxmlformats-officedocument.presentationml.presentation"
".pps"="application/vnd.ms-powerpoint"
".ppsx"="application/vnd.openxmlformats-officedocument.presentationml.slideshow"
".pdf"="application/pdf"
".swf"="application/x-shockwave-flash"
".dll"="application/x-msdownload"
".exe"="application/octet-stream"
".msi"="application/octet-stream"
".chm"="application/octet-stream"
".cab"="application/octet-stream"
".ocx"="application/octet-stream"
".rar"="application/octet-stream"
".tar"="application/x-tar"
".tgz"="application/x-compressed"
".zip"="application/x-zip-compressed"
".z"="application/x-compress"
".wav"="audio/wav"
".wma"="audio/x-ms-wma"
".wmv"="video/x-ms-wmv"
".mp3, .mp2, .mpe, .mpeg, .mpg"="audio/mpeg"
".rm"="application/vnd.rn-realmedia"
".mid, .midi, .rmi"="audio/mid"
".bmp"="image/bmp"
".gif"="image/gif"
".png"="image/png"
".tif, .tiff"="image/tiff"
".jpe, .jpeg, .jpg"="image/jpeg"
".txt"="text/plain"
".xml"="text/xml"
".html"="text/html"
".css"="text/css"
".js"="text/javascript"
".mht, .mhtml"="message/rfc822"

大概率就OK了！！！！！等待大文件联调看效果！！！！！！（其中的延时器是因为我现在测试的文件只有4kb没有进度条效果所以出此下策请辨别哦~~~~）