由于el-upload控件中自定义的upload方法在上传文件中是以FormData的格式上传，后台服务器无法解析这种格式的body，所以通过http-request属性自定义了一个上传方法。
<el-upload ???class="upload-demo" ????ref="upload" ???action="http://127.0.0.1:5000/json/import" ???:http-request="myUpload" ???:on-preview="handlePreview" ???:on-remove="handleRemove" ???:on-error="handleError" ???:on-success="handleSuccess" ???:file-list="fileList" ???:auto-upload="false"> ???<el-button slot="trigger" size="small" type="primary">选取文件</el-button> ???<el-button style="margin-left: 10px;" size="small" type="success" @click="submitUpload">上传到服务器</el-button> ???<div slot="tip" class="el-upload__tip">只能上传json文件，且不超过500kb</div></el-upload>
1 myUpload(content) { 2 ????console.log(‘myUpload...‘); 3 ????this.$axios({ 4 ????????method: ‘post‘, 5 ????????url: content.action, 6 ????????timeout: 20000, 7 ????????data: content.file 8 ????}).then(res => { 9 ????????content.onSuccess(‘配时文件上传成功‘)10 ????}).catch(error => {11 ????????if (error.response) {12 ????????????// The request was made and the server responded with a status code13 ????????????// that falls out of the range of 2xx14 ????????????content.onError(‘配时文件上传失败(‘ + error.response.status + ‘)，‘ + error.response.data);15 ????????} else if (error.request) {16 ????????????// The request was made but no response was received17 ????????????// `error.request` is an instance of XMLHttpRequest in the browser and an instance of18 ????????????// http.ClientRequest in node.js19 ????????????content.onError(‘配时文件上传失败，服务器端无响应‘);20 ????????} else {21 ????????????// Something happened in setting up the request that triggered an Error22 ????????????content.onError(‘配时文件上传失败，请求封装失败‘);23 ????????}24 ????});25 }这种方式很常见，唯一要注意的点是在上传方法调用后判断结果成功或者失败的时候，需要回调el-upload控件的onSuccess和onError方法，为的是能够复用el-upload原生的一些动作，比如如果成功了，页面上的文件列表会有一个绿勾标记上传成功的文件，如果失败则会把失败的文件从文件列表中删除，如果不回调是没有这些功能的。
elementui中el-upload自定义上传方法中遇到的问题
原文地址：https://www.cnblogs.com/rucnevermore/p/8302065.html