formData 传对象和数组、空文件的方法

let infoData = JSON.parse(JSON.stringify(this.infoData));
let formData = new FormData();
// 如果文件不存在，传一个空文件
formData.append("file", this.file || new File([], "file"));
Object.keys(infoData).forEach((list) => {
  if (this.userShow && list == "sysUserVo" && list) {
    infoData[list].roleIdList.map((item, index) => {
      // 数组
      formData.append(
        `sysUserVo.roleIdList[${index}]`,
        infoData[list].roleIdList[index]
      );
    });
    // 对象
    formData.append("sysUserVo.username", infoData[list].username);
    formData.append("sysUserVo.status", infoData[list].status);
  } else if (this.staffShow && list == "companyStaffVo" && list) {
    formData.append(
      "companyStaffVo.departmentId",
      infoData[list].departmentId
    );
    formData.append("companyStaffVo.jobId", infoData[list].jobId);
    formData.append("companyStaffVo.status", infoData[list].status);
  } else if (
    list != "headUrl" &&
    list != "sysUserVo" &&
    list != "companyStaffVo"
  )
    formData.append(list, infoData[list]);
});