Generating pdf in a web API (ItextSharp 5.5.13) - asp.net-web-api

Question

I need to create a PDF file in memory within a web API and send it. I do create the PDF and the web API sends it, but I can't open it once received.
I do create the PDF as a byte array with this:
private byte[] createPDF()
{
MemoryStream memStream = new MemoryStream();
byte[] pdfBytes;
Document doc = new Document(iTextSharp.text.PageSize.LETTER);
PdfWriter wri = PdfWriter.GetInstance(doc, memStream);
doc.AddTitle("test");
doc.AddCreator("I am");
doc.Open();//Open Document to write
Paragraph paragraph = new Paragraph("This is my first line using Paragraph.");
Phrase pharse = new Phrase("This is my second line using Pharse.");
Chunk chunk = new Chunk(" This is my third line using Chunk.");
doc.Add(paragraph);
doc.Add(pharse);
doc.Add(chunk);
pdfBytes = memStream.ToArray();
doc.Close(); //Close
return pdfBytes;
}
This method is called by the method in the web API which sends the PDF, and it is this one:
[HttpGet]
public HttpResponseMessage GetFiniquitopdf()
{
try
{
byte[] buffer = createPDF();
response = new HttpResponseMessage();
response.StatusCode = HttpStatusCode.OK;
response.Content = new StreamContent(new MemoryStream(buffer));
response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
response.Content.Headers.ContentLength = buffer.Length;
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = "myFirstPDF.pdf"
};
}
catch (Exception e)
{
response = Request.CreateErrorResponse(HttpStatusCode.InternalServerError, e.Message);
}
return response;
}
The problem is when the PDF is downloaded it is useless, can't be opened, I don't understand why the PDF can't be opened, I thought it was the security of the Windows 10, so once downloaded I do check it as a secure file, but it doesn't open anyway.
I guess there is something wrong in the way I send it or maybe I lack of something in the creation of the PDF file
thanks in advance

Answer 1

You retrieve the bytes from the memory stream before closing the document:
pdfBytes = memStream.ToArray();
doc.Close(); //Close
return pdfBytes;
But the pdf in the memory stream is not complete before the document is closed. Thus, simply switch the order of instructions:
doc.Close(); //Close
pdfBytes = memStream.ToArray();
return pdfBytes;