如何使用Angular 4将上传的excel文件发送到C# Post API

<input type="file" (change)="onFileSelected($event)" accept=".xlsx">
<button (click)="uploadFile()">上传文件</button>

import { Component } from '@angular/core';
import { FileService } from './file.service';

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

  constructor(private fileService: FileService) { }

  onFileSelected(event: any) {
    this.selectedFile = event.target.files[0];
  }

  uploadFile() {
    this.fileService.uploadFile(this.selectedFile).subscribe(
      response => {
        console.log('文件上传成功');
      },
      error => {
        console.error('文件上传失败:', error);
      }
    );
  }
}

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

@Injectable({
  providedIn: 'root'
})
export class FileService {
  private apiUrl = 'http://your-api-url'; // 替换为实际的API地址

  constructor(private http: HttpClient) { }

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

    return this.http.post(this.apiUrl, formData);
  }
}

[HttpPost]
public IActionResult UploadFile(IFormFile file)
{
    // 处理接收到的文件数据，例如保存到数据库或进行其他业务逻辑处理
    // 返回相应的结果
    return Ok();
}