Corrupt PDF Attachment

Question

I am attempting to do the following:

1. Retrieve a generated pdf from a web page
2. Create an email message
3. Attach the pdf to the message
4. Send the message

I am able to retrieve the pdf from the web page and send the message with it as an attachment. However, when I try to open the attachment, I get the dreaded "Adobe Reader could not open 'filename.pdf' because it is either not a supported file type or because the file has been damaged" message.

The pdf is generated by an MVC3 page using a custom ActionResult to return the pdf. It looks like this

public class EnrollmentExpectationsPdfResult : FileResult
{
    IList<AdminRepEnrollmentExpectationViewModel> adminreps;

    public EnrollmentExpectationsPdfResult(IList<AdminRepEnrollmentExpectationViewModel> adminrep)
        : this("application/pdf", adminrep)
    { }

    public EnrollmentExpectationsPdfResult(string contentType, IList<AdminRepEnrollmentExpectationViewModel> adminrep)
        : base(contentType)
    {
        adminreps = adminrep;

    }

    protected override void WriteFile(HttpResponseBase response)
    {
        var cd = new ContentDisposition
        {
            Inline = true,
            FileName = "MyPDF.pdf"
        };
        response.AppendHeader("Content-Disposition", cd.ToString());

        //Skip a bunch of boring font stuff
        ...

        var writer = PdfWriter.GetInstance(doc, response.OutputStream);
        writer.PageEvent = new EnrollmentExpectationPDFPageEvent();            
        doc.Open();

        //Skip the doc writing stuff
        ...

        doc.Close();
    }
}

The controller method is here

public ActionResult EnrollmentExpectationsPDF()
{
    //skip a bunch a database stuff
    ...
    return new EnrollmentExpectationsPdfResult(adminList);
}

Here is the code at the heart of the problem...

//Get PDF
CredentialCache cc = new CredentialCache();
cc.Add(
       new Uri("http://myserver/mypdfgeneratingpage"),
       "NTLM",
       new NetworkCredential("myusername", "mypassword"));

var webRequestObject = (HttpWebRequest)WebRequest.Create("http://iapps.national.edu/erp/Reports/EnrollmentExpectationsPDF");
webRequestObject.Credentials = cc;
var response = webRequestObject.GetResponse();
var webStream = response.GetResponseStream();

//Create Mail
System.Net.Mail.MailMessage eMail = ...

//Skipping to attachment stuff
ContentType ct = new ContentType()
{
     MediaType = MediaTypeNames.Application.Pdf,
     Name = "EnrollmentExpecations_2.pdf"
};

Attachment a = new Attachment(webStream, ct);
eMail.Attachments.Add(a);

//Send Message
....

As an experiment, I tried writing the downloaded file to disk

MemoryStream ms = new MemoryStream();
var fileStream = File.Create("C:\\MyPDF.pdf");
webStream.CopyTo(fileStream);

Viola, I am able to open the file from the diskwithout a problem.

What am I missing in order to make the attachment readable?

Answer 1

Just to make it clear to users, thanks to @rlb.usa

"Make sure you close and flush your stream after you send the object"

Answer 2

For us, the answer was different.

The issue was when writing to the database, we were using GetBuffer() instead of ToArray(). So if the buffer was 256, then the remaining amount was appended to the document in the database as null characters.

I found the answer here http://forums.asp.net/t/1083910.aspx

I don't think the error is in your code for downloading the document. I believe the error is happening because of how the document is originally stored in the database. Make sure you aren't using the GetBuffer() method when writing the file to the database. Try using ToArray() instead and it will not append extra characters to the end of your file stream. Here's a link to give you some more details: http://msdn.microsoft.com/en-us/library/system.io.memorystream.getbuffer.aspx

The extra characters after the %%EOF tag at the end of your PDF document are most likely what is causing the message: