vue+elementui自定义上传文件

<el-upload                class="upload-demo"                action="#"                ref="upload"                :http-request="httpRequest"                :on-preview="handlePreview"                :on-remove="handleRemove"                :on-change="onChange"                multiple                :on-exceed="handleExceed"                :file-list="fileList"                :auto-upload="false"                accept=".txt,.csv"              >                <el-button slot="trigger" size="small"                  ><IconClass                    icon-class="iconcloud-upload"                  />上传文件</el-button                >                <div slot="tip" class="el-upload__tip">                  反对.txt、 .csv格局                </div>              </el-upload>
submitUpload() {      return new Promise((resolve, reject) => {        this.$refs.upload.submit();        const data = new FormData();        this.fileList.forEach(file => {          data.append("file", file.raw);          //此处肯定是append file.raw 上传文件只需保护fileList file.raw.name要加上        });        //后盾接口        uploadDatasource(data)          .then(res => {            if (res.code == 200) {              resolve(res.data);            } else {              reject(res.msg);            }            this.fileList = [];          })          .catch(err => {            this.fileList = [];            console.log(err);          });      });    },