如何在Angular 6中使用ADDMORE按钮上传多个文件？

<input type="file" multiple (change)="onFileSelected($event)">
<button (click)="uploadFiles()">ADDMORE</button>

selectedFiles: File[] = [];

onFileSelected(event: any) {
  this.selectedFiles = event.target.files;
}

import { HttpClient } from '@angular/common/http';

constructor(private http: HttpClient) {}

uploadFiles() {
  const formData = new FormData();
  for (let file of this.selectedFiles) {
    formData.append('files', file);
  }

  this.http.post('your-upload-url', formData).subscribe(
    (response) => {
      console.log('Files uploaded successfully!');
    },
    (error) => {
      console.error('Error uploading files:', error);
    }
  );
}