如何在angular2中向客户post请求发送文件参数

npm install @angular/common @angular/forms

import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { FormBuilder, FormGroup } from '@angular/forms';

@Component({
  selector: 'app-file-upload',
  templateUrl: './file-upload.component.html',
  styleUrls: ['./file-upload.component.css']
})
export class FileUploadComponent {
  fileForm: FormGroup;

  constructor(private http: HttpClient, private formBuilder: FormBuilder) {
    this.fileForm = this.formBuilder.group({
      file: ['']
    });
  }

  onFileChange(event) {
    if (event.target.files.length > 0) {
      const file = event.target.files[0];
      this.fileForm.get('file').setValue(file);
    }
  }

  onSubmit() {
    const formData = new FormData();
    formData.append('file', this.fileForm.get('file').value);

    this.http.post('your-api-url', formData)
      .subscribe(response => {
        console.log(response);
      });
  }
}

<form [formGroup]="fileForm" (ngSubmit)="onSubmit()">
  <input type="file" (change)="onFileChange($event)">
  <button type="submit">Upload</button>
</form>