valin077 valin077 - 28 days ago 20
C# Question

iTextSharp creation of a pdf from a list of byte arrays

I've got a list of byte[] which i'd like to concatenate into one byte[] which will be the final PDf.

On the "page = copy.GetImportedPage(new PdfReader(p), i); " i'm getting an "object reference not set to an instance error.

I've got no clue of what's going on, i've already checked every object and there's no null.

Any ideas on this, or another piece of code that could make the trick?!

I've got this method:

EDIT

public static byte[] concatAndAddContent(List<byte[]> pdf)
{
byte [] todos;

using(MemoryStream ms = new MemoryStream())
{
Document doc = new Document();
doc.Open();

PdfCopy copy = new PdfCopy(doc, ms);
PdfCopyFields copy2 = new PdfCopyFields(ms);


PdfReader reader;
foreach (byte[] p in pdf)
{
reader = new PdfReader(p);
int pages = reader.NumberOfPages;

// loop over document pages
for (int i = 1; i < pages; i++)
{
PdfImportedPage page = copy.GetImportedPage(reader, i);
PdfCopy.PageStamp stamp = copy.CreatePageStamp(page);
PdfContentByte cb = stamp.GetUnderContent();
cb.SaveState();
stamp.AlterContents();
copy.AddPage(page);
}
}

doc.Close();
todos = ms.GetBuffer();
ms.Flush();
ms.Dispose();
}

return todos;
}


Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
iTextSharp.text.pdf.PdfImportedPage..ctor(PdfReaderInstance readerInstance, PdfWriter writer, Int32 pageNumber) +45
iTextSharp.text.pdf.PdfReaderInstance.GetImportedPage(Int32 pageNumber) +175
iTextSharp.text.pdf.PdfCopy.GetImportedPage(PdfReader reader, Int32 pageNumber) +256
SAM.Web.Classes.UtileriasReportes.concatAndAddContent(List`1 pdf) in \Classes\UtileriasReportes.cs:199
SAM.Web.Classes.UtileriasReportes.ObtenReporteOdt(Int32 ordenTrabajoID, Boolean caratula, Boolean juntas, Boolean cortes, Boolean materiales, Boolean resumenMateriales)

in D:\MIMOSS\Desarrollo\SAM 2.0\Desarrollo\WebSolution\SAM.Web\Classes\UtileriasReportes.cs:168
SAM.Web.Produccion.PopupImpresionOdt.btnImprimir_Click(Object sender, EventArgs e) in \PopupImpresionOdt.aspx.cs:44
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +118
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +112
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5563


thanks for your time!

Answer

I've figured it out, just so everbody can have the solution: here it is:

    public static byte[] concatAndAddContent(List<byte[]> pdf)
    {
        byte [] all;

        using(MemoryStream ms = new MemoryStream())
        {
            Document doc = new Document();

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

            doc.SetPageSize(PageSize.LETTER);
            doc.Open();
            PdfContentByte cb = writer.DirectContent;
            PdfImportedPage page;

            PdfReader reader;
            foreach (byte[] p in pdf)
            {
                reader = new PdfReader(p);
                int pages = reader.NumberOfPages;

                // loop over document pages
                for (int i = 1; i <= pages; i++)
                {
                    doc.SetPageSize(PageSize.LETTER);
                    doc.NewPage();
                    page = writer.GetImportedPage(reader, i);
                    cb.AddTemplate(page, 0, 0);
                }
            }

            doc.Close();
            all = ms.GetBuffer();
            ms.Flush();
            ms.Dispose();
        }

        return all;
    }

Hope that helps!