如何发送带有附件的Angular .Netcore应用程序的电子邮件？

// 在组件中引入HttpClient模块
import { HttpClient } from '@angular/common/http';

// 在组件中定义发送邮件的方法
sendEmailWithAttachment() {
  const formData = new FormData();
  formData.append('recipient', this.recipient);
  formData.append('subject', this.subject);
  formData.append('body', this.body);
  formData.append('attachment', this.attachment);

  this.http.post('/api/sendEmail', formData).subscribe(
    response => {
      console.log('Email sent successfully');
    },
    error => {
      console.error('Failed to send email');
    }
  );
}

// 在控制器中定义发送邮件的API接口
[HttpPost("sendEmail")]
public IActionResult SendEmailWithAttachment([FromForm] EmailModel emailModel)
{
    using (var message = new MailMessage())
    {
        message.To.Add(emailModel.Recipient);
        message.Subject = emailModel.Subject;
        message.Body = emailModel.Body;

        // 添加附件
        if (emailModel.Attachment != null && emailModel.Attachment.Length > 0)
        {
            using (var memoryStream = new MemoryStream())
            {
                emailModel.Attachment.CopyTo(memoryStream);
                message.Attachments.Add(new Attachment(memoryStream, emailModel.Attachment.FileName));
            }
        }

        // 配置SMTP服务器和端口
        using (var smtpClient = new SmtpClient("smtp.example.com", 587))
        {
            smtpClient.Credentials = new NetworkCredential("username", "password");
            smtpClient.EnableSsl = true;

            // 发送邮件
            smtpClient.Send(message);
        }
    }

    return Ok();
}

// 定义邮件模型
public class EmailModel
{
    public string Recipient { get; set; }
    public string Subject { get; set; }
    public string Body { get; set; }
    public IFormFile Attachment { get; set; }
}