C#附加到MailMessage对象时为空文件

当我的应用程序崩溃时，我试图发送一封电子邮件，附带了一个描述问题的文件（错误详细信息是从数据库收集的）。我尝试过在不将文件附加到电子邮件的情况下创建该文件，但效果很好（使用从数据库收集的数据）。下面是一个非常接近我的例子：

MailMessage mailMessage = new MailMessage();
mailMessage.To.Add("Address1@test.com");
mailMessage.From = new MailAddress("Address2@test.com");
mailMessage.Subject = "Subject";
mailMessage.Body = "Body";

FileStream fs = new FileStream("Test.txt", FileMode.Create, FileAccess.ReadWrite);
StreamWriter sw = new StreamWriter(fs);
sw.WriteLine("Text");

Attachment attach = new Attachment(fs, "Test.txt", "Text/Plain");
mailMessage.Attachments.Add(attach);

SmtpClient smtp = new SmtpClient();

try
{
    smtp.Send(mailMessage);
}
catch(Exception ex)
{
     MessageBox.Show(ex.Message + Environment.NewLine + ex.InnerException);
}

sw.Close();

我还尝试：

MailMessage mailMessage = new MailMessage();
mailMessage.To.Add("Address1@test.com");
mailMessage.From = new MailAddress("Address2@test.com");
mailMessage.Subject = "Subject";
mailMessage.Body = "Body";

using (FileStream fs = new FileStream("Test.txt", FileMode.Create, FileAccess.ReadWrite))
{
     StreamWriter sw = new StreamWriter(fs);
     sw.WriteLine("Text");


     Attachment attach = new Attachment(fs, "Test.txt", "Text/Plain");
     mailMessage.Attachments.Add(attach);

     SmtpClient smtp = new SmtpClient();

     try
     {
         smtp.Send(mailMessage);
     }
     catch (Exception ex)
     {
          MessageBox.Show(ex.Message + Environment.NewLine + ex.InnerException);
     }
}

该文件已附加到电子邮件，大小为，但为空。我做错了什么

提前谢谢

using (FileStream fs = new FileStream("Test.txt", FileMode.Create, FileAccess.ReadWrite))
{
    StreamWriter sw = new StreamWriter(fs);
    sw.WriteLine("Text");
    sw.Close();
}

MailMessage mailMessage = new MailMessage();
mailMessage.To.Add("Address1@test.com");
mailMessage.From = new MailAddress("Address2@test.com");
mailMessage.Subject = "Subject";
mailMessage.Body = "Body";


 Attachment attach = new Attachment("Test.txt", "Text/Plain"); //add a complete file path if needed
 mailMessage.Attachments.Add(attach);

 SmtpClient smtp = new SmtpClient();

 try
 {
     smtp.Send(mailMessage);
 }
 catch (Exception ex)
 {
      MessageBox.Show(ex.Message + Environment.NewLine + ex.InnerException);
 }

---

}回答我自己的问题。。。找到了答案

以下是我使用的代码：

MailMessage mailMessage = new MailMessage();
mailMessage.To.Add("Address1@test.com");
mailMessage.From = new MailAddress("Address2@test.com");
mailMessage.Subject = "Subject";
mailMessage.Body = "Body";

using (MemoryStream memoryStream = new MemoryStream())
{
     byte[] contentAsBytes = Encoding.UTF8.GetBytes("Test");
     memoryStream.Write(contentAsBytes, 0, contentAsBytes.Length);

     memoryStream.Seek(0, SeekOrigin.Begin);
     ContentType contentType = new ContentType();
     contentType.MediaType = MediaTypeNames.Text.Plain;
     contentType.Name = "Test.txt";

      Attachment attach = new Attachment(memoryStream, contentType);
      mailMessage.Attachments.Add(attach);

      SmtpClient smtp = new SmtpClient();

      try
      {
          smtp.Send(mailMessage);
      }
      catch (Exception ex)
      {
          MessageBox.Show(ex.Message + Environment.NewLine + ex.InnerException);
      }
}

我使用了内存流而不是文件流。我还创建了一个内容类型对象，而不仅仅是在附件构造函数中指定MediaType

---

谢谢大家的帮助。

在附加文件之前尝试完成文件的编写（关闭软件）。是否检查了路径是否正确，并请提供catch（）生成的错误输出谢谢您的评论。jac，文件在附加之前不能关闭，否则它会崩溃，表明文件已关闭。esunic，没有生成错误。创建的文件没有错误，但为空。如果在

smtp.Send（）

之前执行此操作，则应能正常工作。正如@esunic所说，

StreamWriter

只在关闭时执行刷新。如果您只需将

sw.Close（）

放在

smtp.Send（）

之前，您的原始代码就可以工作了。谢谢，太好了！这导致我在一些代码中解决了同样的问题。如果你好奇，它是

memoryStream.Seek（0，SeekOrigin.Begin）这是解决问题的方法。