Itext.Sharp Document to byte array problme - asp.net-mvc

Question

I have the following code:
public byte[] ExportToPdf(DataTable dt)
{
iTextSharp.text.Document document = new iTextSharp.text.Document();
document.Open();
iTextSharp.text.Font font5 = iTextSharp.text.FontFactory.GetFont(FontFactory.HELVETICA, 5);
PdfPTable table = new PdfPTable(dt.Columns.Count);
PdfPRow row = null;
float[] widths = new float[] { 4f, 4f, 4f, 4f, 4f, 4f, 4f, 4f };
table.SetWidths(widths);
table.WidthPercentage = 100;
foreach (DataColumn c in dt.Columns)
{
table.AddCell(new Phrase(c.ColumnName, font5));
}
document.Add(table);
document.Close();
byte[] bytes;
MemoryStream msPDFData = new MemoryStream();
PdfWriter writer = PdfWriter.GetInstance(document, msPDFData);
return msPDFData.ToArray();
}
And in another function i call the function like this:
byte[] bytes = ExportToPdf(table);
return File(bytes, "application/pdf", "RaportDocumenteEmise.pdf");
When i try to open the pdf it says that is damaged.
Somehow the byte array is empty.
Can say me what am i doing wrong?

Answer 1

This is wrong:
iTextSharp.text.Document document = new iTextSharp.text.Document();
document.Open();
A PDF is created using 5 simple steps:
Create a Document object
Create a PdfWriter instance
Open the document
Add content
Close the document
You don't have step 2. In your comment, you say that you've solved the problem by creating that instance after opening the document, but that's wrong! You need to create the PdfWriter instance before opening the document.
Opening the document writes the PDF header to the OutputStream. That can't happen without a valid PdfWriter instance.

Answer 2

I was trying to do the same thing as you.
After many tries, I discovered that if I put PdfWriter.GetInstance
inside using (var ms = new MemoryStream()) { } everything works alright!
My full code is:
public FileContentResult GetPDF() {
string htmlContent = "<p>First line</p><p>Second line</p>";
StringReader sr = new StringReader(htmlContent);
Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 100f, 0f);
HTMLWorker hw= new HTMLWorker(pdfDoc);
FileContentResult result;
using (var ms = new MemoryStream()) {
PdfWriter.GetInstance(pdfDoc, ms);
pdfDoc.Open();
hw.Parse(sr);
pdfDoc.Close();
result = this.File(ms.ToArray(), "application/pdf", "teste.pdf");
}
return result;
}
Ps.: This is a method inside my Controller.