iTextSharp - Sending in-memory pdf in an email attachment

Have you tried:

PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream);

// Build pdf code...

writer.CloseStream = false;
doc.Close();

// Build email

memoryStream.Position = 0;
mm.Attachments.Add(new Attachment(memoryStream, "test.pdf"));

If my memory serves me correctly, this solved a similar problem in a previous project.

See http://forums.asp.net/t/1093198.aspx

I tried the code posted by brianng and it worked. Just change the top of the code to this:

var doc = new Document();
MemoryStream memoryStream = new MemoryStream();
PdfWriter writer = PdfWriter.GetInstance(doc, memoryStream); //capture the object
doc.Open();
doc.Add(new Paragraph("First Paragraph"));
doc.Add(new Paragraph("Second Paragraph"));
writer.CloseStream = false; //set the closestream property
doc.close(); //close the document without closing the underlying stream
memoryStream.Position = 0;

/* remainder of your code stays the same*/

Can you flush the document or memory stream and then close it after you attach it?

Probably calling doc.Close() Disposes the underlying stream. Try removing doc.Close() and instead of that line set memoryStream.Position = 0;

Alternatively you can use a temp file:

var tempFilePath = Path.GetTempFileName();

try 
{           
    var doc = new Document();

    PdfWriter.GetInstance(doc, File.OpenWrite(tempFilePath));
    doc.Open();
    doc.Add(new Paragraph("First Paragraph"));
    doc.Add(new Paragraph("Second Paragraph"));

    doc.Close();

    MailMessage mm = new MailMessage("[email protected]", "[email protected]")
    {
        Subject = "subject",
        IsBodyHtml = true,
        Body = "body"
    };

    mm.Attachments.Add(new Attachment(tempFilePath, "test.pdf"));
    SmtpClient smtp = new SmtpClient
    {
        Host = "smtp.gmail.com",
        Port = 587,
        EnableSsl = true,
        Credentials = new NetworkCredential("[email protected]", "my_password")
    };

    smtp.Send(mm);
}
finally
{
    File.Delete(tempFilePath);
}