如何在angular7中将数据传递到FileUploader

Question

我的代码将文件发送到node.js服务器，并且正在100％工作，但是我想传递一些数据，例如用户ID或UserName。我该怎么办？

HTML组件：

<form>
<input type="file" name="photo"  ng2FileSelect [uploader]="uploader">
<button type="button" (click)="uploader.uploadAll()">Upload an Image</button>
</form>

Ts组件：

import { Component, OnInit } from '@angular/core';
import { FileUploader} from 'ng2-file-upload/ng2-file-upload';
@Component({
  selector: 'app-photos',
  templateUrl: './photos.component.html',
  styleUrls: ['./photos.component.css']
})
export class PhotosComponent implements OnInit {

public uploader: FileUploader = new FileUploader({ url: URL, itemAlias: 'photo'});

ngOnInit() {
   this.uploader.onAfterAddingFile = (file) => { file.withCredentials = false; };
   this.uploader.onCompleteItem = (item: any, response: any, status: any, headers: any) => {
   alert('File uploaded successfully');
    }
  }


// this function to Get Information of user
  getUser() {
    this.userservice.GetUserById(this.user._id).subscribe(
      data => {
        this.user = data.result;
},
      err => console.log(err)
    );
  }
}