Angular8 http客户端表单数据上载

import { Component } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';

@Component({
  selector: 'app-upload-form',
  templateUrl: './upload-form.component.html',
  styleUrls: ['./upload-form.component.css']
})
export class UploadFormComponent {
  fileToUpload: File = null;

  constructor(private http: HttpClient) { }

  handleFileInput(files: FileList) {
    this.fileToUpload = files.item(0);
  }

  uploadFile() {
    const formData: FormData = new FormData();
    formData.append('file', this.fileToUpload, this.fileToUpload.name);

    const headers = new HttpHeaders();
    headers.append('Content-Type', 'multipart/form-data');

    this.http.post('http://example.com/upload', formData, { headers: headers })
      .subscribe(response => {
        console.log(response);
      });
  }
}

<input type="file" (change)="handleFileInput($event.target.files)">
<button (click)="uploadFile()">Upload</button>