文件上传，其实就是用el-upload组件来实现上传，只是换了样式，和图片上传一样

<el-form-item label="选择文件">
          <el-input placeholder="请选择文件" v-model="form.file" disabled style="width: 450px">
            <el-upload slot="append" :show-file-list="false" :headers="headers" accept=".xlsx" action="/api/follow-admin/data-import-info/import" :before-upload="handleUploadBefore" :on-success="handleUploadSuccess">
              <el-button size="small" type="primary">点击上传</el-button>
            </el-upload>
          </el-input>

          <p style="font-size: 12px; color: #e6a23c">文件大小不可大于10M且必须按照模版格式进行上传，仅支持xls/xlsx格式文件</p>
        </el-form-item>


 // 上传前事件
    handleUploadBefore (file) {
      const isLt2M = file.size / 1024 / 1024 < 1
      if (!isLt2M) {
        this.$message.warning('文件大小不能超过 1M')
      }
      return isLt2M
    },
    // 上传成功处理
    handleUploadSuccess (res) {
      if (res.code === 200) {
        this.$message.success('导入成功')
        this.form.file = res.data
        this.getTableDataList()
      } else {
        this.$message.error(res.msg)
      }
    }


<style lang="less" scoped>
.resident-export-data-manage {
  .table-bg {
    padding: 20px !important;
    min-height: auto !important;
    ::v-deep .el-form {
      .el-form-item {
        &:nth-child(2) {
          .el-form-item__content {
            .el-input {
              .el-input-group__append {
                background-color: #136fe0 !important;
                span {
                  color: #fff;
                }
              }
            }
          }
        }
      }
    }
  }
}
</style>