iTextSharp - 在电子邮件附件中发送内存中的 pdf

我在这里问了几个问题，但仍有问题.如果您能告诉我我在代码中做错了什么，我将不胜感激.我从 ASP.Net 页面运行上面的代码并得到无法访问关闭的流".

I've asked a couple of questions here but am still having issues. I'd appreciate if you could tell me what I am doing wrong in my code. I run the code above from a ASP.Net page and get "Cannot Access a Closed Stream".

var doc = new Document();

MemoryStream memoryStream = new MemoryStream();

PdfWriter.GetInstance(doc, memoryStream);
doc.Open();
doc.Add(new Paragraph("First Paragraph"));
doc.Add(new Paragraph("Second Paragraph"));

doc.Close(); //if I remove this line the email attachment is sent but with 0 bytes 

MailMessage mm = new MailMessage("username@gmail.com", "username@gmail.com")
{
    Subject = "subject",
    IsBodyHtml = true,
    Body = "body"
};

mm.Attachments.Add(new Attachment(memoryStream, "test.pdf"));
SmtpClient smtp = new SmtpClient
{
    Host = "smtp.gmail.com",
    Port = 587,
    EnableSsl = true,
    Credentials = new NetworkCredential("username@gmail.com", "my_password")
};

smtp.Send(mm); //the "Cannot Access a Closed Stream" error is thrown here

谢谢！！！

为了帮助寻找这个问题的答案的人，发送一个 pdf 文件附加到电子邮件而无需实际创建文件的代码如下(感谢 Ichiban 和 Brianng):

Just to help somebody looking for the answer to this question, the code to send a pdf file attached to an email without having to physically create the file is below (thanks to Ichiban and Brianng):

var doc = new Document();
MemoryStream memoryStream = new MemoryStream();
PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream);

doc.Open();
doc.Add(new Paragraph("First Paragraph"));
doc.Add(new Paragraph("Second Paragraph"));

writer.CloseStream = false;
doc.Close();
memoryStream.Position = 0;

MailMessage mm = new MailMessage("username@gmail.com", "username@gmail.com")
{
    Subject = "subject",
    IsBodyHtml = true,
    Body = "body"
};

mm.Attachments.Add(new Attachment(memoryStream, "filename.pdf"));
SmtpClient smtp = new SmtpClient
{
    Host = "smtp.gmail.com",
    Port = 587,
    EnableSsl = true,
    Credentials = new NetworkCredential("username@gmail.com", "password")

};

smtp.Send(mm);