记录：基于vue和element实现文件上传进度条```js //进度条 //函数 uploadVideoProcess

                 <el-upload
                    action=""
                    accept=".JPG, .PNG, .JPEG,.jpg, .png, .jpeg, .dcm,.mp4" //上传文件的格式
                    :show-file-list="false" 
                    :on-progress="uploadVideoProcess" //所需的函数
                  >
                    <img width="20" src="../assets/img/project.png" />
                  </el-upload>

                   //进度条
                 <el-progress
                    :percentage="videoUploadPercent"
                    status="success"
                  ></el-progress>


                //函数
                uploadVideoProcess(event, file, fileList) {
                  this.videoUploadPercent = Math.floor(event.percent);
                    },