Comment fusionner plusieurs fichiers pdf (générés en temps d'exécution)?

j'ai utilisé iTextsharp avec c# pour combiner des fichiers pdf. C'est le code que j'ai utilisé.

string[] lstFiles=new string[3];
    lstFiles[0]=@"C:/pdf/1.pdf";
    lstFiles[1]=@"C:/pdf/2.pdf";
    lstFiles[2]=@"C:/pdf/3.pdf";

    PdfReader reader = null;
    Document sourceDocument = null;
    PdfCopy pdfCopyProvider = null;
    PdfImportedPage importedPage;
    string outputPdfPath=@"C:/pdf/new.pdf";


    sourceDocument = new Document();
    pdfCopyProvider = new PdfCopy(sourceDocument, new System.IO.FileStream(outputPdfPath, System.IO.FileMode.Create));

    //Open the output file
    sourceDocument.Open();

    try
    {
        //Loop through the files list
        for (int f = 0; f < lstFiles.Length-1; f++)
        {
            int pages =get_pageCcount(lstFiles[f]);

            reader = new PdfReader(lstFiles[f]);
            //Add pages of current file
            for (int i = 1; i <= pages; i++)
            {
                importedPage = pdfCopyProvider.GetImportedPage(reader, i);
                pdfCopyProvider.AddPage(importedPage);
            }

            reader.Close();
         }
        //At the end save the output file
        sourceDocument.Close();
    }
    catch (Exception ex)
    {
        throw ex;
    }


private int get_pageCcount(string file)
{
    using (StreamReader sr = new StreamReader(File.OpenRead(file)))
    {
        Regex regex = new Regex(@"/Type\s*/Page[^s]");
        MatchCollection matches = regex.Matches(sr.ReadToEnd());

        return matches.Count;
    }
}

Voici un code que j'ai tirée d'un vieux projet que j'avais. C'était une application web mais j'utilisais iTextSharp pour fusionner des fichiers pdf puis les imprimer.

public static class PdfMerger
    {
        /// <summary>
        /// Merge pdf files.
        /// </summary>
        /// <param name="sourceFiles">PDF files being merged.</param>
        /// <returns></returns>
        public static byte[] MergeFiles(List<Stream> sourceFiles)
        {
            Document document = new Document();
            MemoryStream output = new MemoryStream();

            try
            {
                // Initialize pdf writer
                PdfWriter writer = PdfWriter.GetInstance(document, output);
                writer.PageEvent = new PdfPageEvents();

                // Open document to write
                document.Open();
                PdfContentByte content = writer.DirectContent;

                // Iterate through all pdf documents
                for (int fileCounter = 0; fileCounter < sourceFiles.Count; fileCounter++)
                {
                    // Create pdf reader
                    PdfReader reader = new PdfReader(sourceFiles[fileCounter]);
                    int numberOfPages = reader.NumberOfPages;

                    // Iterate through all pages
                    for (int currentPageIndex = 1; currentPageIndex <=
                                        numberOfPages; currentPageIndex++)
                    {
                        // Determine page size for the current page
                        document.SetPageSize(
                            reader.GetPageSizeWithRotation(currentPageIndex));

                        // Create page
                        document.NewPage();
                        PdfImportedPage importedPage =
                            writer.GetImportedPage(reader, currentPageIndex);


                        // Determine page orientation
                        int pageOrientation = reader.GetPageRotation(currentPageIndex);
                        if ((pageOrientation == 90) || (pageOrientation == 270))
                        {
                            content.AddTemplate(importedPage, 0, -1f, 1f, 0, 0,
                                reader.GetPageSizeWithRotation(currentPageIndex).Height);
                        }
                        else
                        {
                            content.AddTemplate(importedPage, 1f, 0, 0, 1f, 0, 0);
                        }
                    }
                }
            }
            catch (Exception exception)
            {
                throw new Exception("There has an unexpected exception" +
                        " occured during the pdf merging process.", exception);
            }
            finally
            {
                document.Close();
            }
            return output.GetBuffer();
        }
    }



    /// <summary>
    /// Implements custom page events.
    /// </summary>
    internal class PdfPageEvents : IPdfPageEvent
    {
        #region members
        private BaseFont _baseFont = null;
        private PdfContentByte _content;
        #endregion

        #region IPdfPageEvent Members
        public void OnOpenDocument(PdfWriter writer, Document document)
        {
            _baseFont = BaseFont.CreateFont(BaseFont.HELVETICA,
                                BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
            _content = writer.DirectContent;
        }

        public void OnStartPage(PdfWriter writer, Document document)
        { }

        public void OnEndPage(PdfWriter writer, Document document)
        { }

        public void OnCloseDocument(PdfWriter writer, Document document)
        { }

        public void OnParagraph(PdfWriter writer,
                    Document document, float paragraphPosition)
        { }

        public void OnParagraphEnd(PdfWriter writer,
                    Document document, float paragraphPosition)
        { }

        public void OnChapter(PdfWriter writer, Document document,
                                float paragraphPosition, Paragraph title)
        { }

        public void OnChapterEnd(PdfWriter writer,
                    Document document, float paragraphPosition)
        { }

        public void OnSection(PdfWriter writer, Document document,
                    float paragraphPosition, int depth, Paragraph title)
        { }

        public void OnSectionEnd(PdfWriter writer,
                    Document document, float paragraphPosition)
        { }

        public void OnGenericTag(PdfWriter writer, Document document,
                                    Rectangle rect, string text)
        { }
        #endregion

        private float GetCenterTextPosition(string text, PdfWriter writer)
        {
            return writer.PageSize.Width / 2 - _baseFont.GetWidthPoint(text, 8) / 2;
        }
    }

Je n'ai pas écrit ceci, mais j'ai fait quelques modifications. Je ne me souviens pas où je l'ai trouvé. Après avoir fusionné les PDF, j'appellerais cette méthode pour insérer javascript pour ouvrir la boîte de dialogue d'impression lorsque le PDF est ouvert. Si vous changez bSilent en true, alors il devrait s'imprimer silencieusement à leur défaut imprimante.

public Stream addPrintJStoPDF(Stream thePDF)
{
    MemoryStream outPutStream = null;
    PRStream finalStream = null;
    PdfDictionary page = null;
    string content = null;

    //Open the stream with iTextSharp
    var reader = new PdfReader(thePDF);

    outPutStream = new MemoryStream(finalStream.GetBytes());
    var stamper = new PdfStamper(reader, (MemoryStream)outPutStream);
    var jsText = "var res = app.setTimeOut('this.print({bUI: true, bSilent: false, bShrinkToFit: false});', 200);";
    //Add the javascript to the PDF
    stamper.JavaScript = jsText;

    stamper.FormFlattening = true;
    stamper.Writer.CloseStream = false;
    stamper.Close();

    //Set the stream to the beginning
    outPutStream.Position = 0;

    return outPutStream;
}

Je ne sais pas si le code ci-dessus est bien écrit puisque je l'ai tiré d'ailleurs et je n'ai pas travaillé en profondeur du tout avec iTextSharp mais je sais que cela a fonctionné à la fusion de fichiers PDF que je générais à l'exécution.

Testé avec iTextSharp-LGPL 4.1.6:

    public static byte[] ConcatenatePdfs(IEnumerable<byte[]> documents)
    {
        using (var ms = new MemoryStream())
        {
            var outputDocument = new Document();
            var writer = new PdfCopy(outputDocument, ms);
            outputDocument.Open();

            foreach (var doc in documents)
            {
                var reader = new PdfReader(doc);
                for (var i = 1; i <= reader.NumberOfPages; i++)
                {
                    writer.AddPage(writer.GetImportedPage(reader, i));
                }
                writer.FreeReader(reader);
                reader.Close();
            }

            writer.Close();
            outputDocument.Close();
            var allPagesContent = ms.GetBuffer();
            ms.Flush();

            return allPagesContent;
        }
    }

pour éviter les problèmes de mémoire mentionnés, j'ai utilisé file stream au lieu de memory stream (mentionné dans ITextSharp de mémoire exception de la fusion de plusieurs pdf) pour fusionner les fichiers pdf:

        var parentDirectory = Directory.GetParent(SelectedDocuments[0].FilePath);
        var savePath = parentDirectory + "\MergedDocument.pdf";

        using (var fs = new FileStream(savePath, FileMode.Create))
        {
            using (var document = new Document())
            {
                using (var pdfCopy = new PdfCopy(document, fs))
                {
                    document.Open();
                    for (var i = 0; i < SelectedDocuments.Count; i++)
                    {
                        using (var pdfReader = new PdfReader(SelectedDocuments[i].FilePath))
                        {
                            for (var page = 0; page < pdfReader.NumberOfPages;)
                            {
                                pdfCopy.AddPage(pdfCopy.GetImportedPage(pdfReader, ++page));
                            }
                        }
                    }
                }
            }
        }

****/*For Multiple PDF Print..!!*/****

<button type="button" id="btnPrintMultiplePdf" runat="server" class="btn btn-primary btn-border btn-sm"
                                                                onserverclick="btnPrintMultiplePdf_click">
                                                                <i class="fa fa-file-pdf-o"></i>Print Multiple pdf</button>

protected void btnPrintMultiplePdf_click(object sender, EventArgs e)
    {
        if (ValidateForMultiplePDF() == true)
        {
            #region Declare Temp Variables..!!
            CheckBox chkList = new CheckBox();
            HiddenField HidNo = new HiddenField();

            string Multi_fofile, Multi_listfile;
            Multi_fofile = Multi_listfile = "";
            Multi_fofile = Server.MapPath("PDFRNew");
            #endregion

            for (int i = 0; i < grdRnew.Rows.Count; i++)
            {
                #region Find Grd Controls..!!
                CheckBox Chk_One = (CheckBox)grdRnew.Rows[i].FindControl("chkOne");
                Label lbl_Year = (Label)grdRnew.Rows[i].FindControl("lblYear");
                Label lbl_No = (Label)grdRnew.Rows[i].FindControl("lblCode");
                #endregion

                if (Chk_One.Checked == true)
                {
                    HidNo .Value = llbl_No .Text.Trim()+ lbl_Year .Text;

                    if (File.Exists(Multi_fofile + "\" + HidNo.Value.ToString() + ".pdf"))
                    {
                        #region Get Multiple Files Name And Paths..!!
                        if (Multi_listfile != "")
                        {
                            Multi_listfile = Multi_listfile + ",";
                        }
                        Multi_listfile = Multi_listfile + Multi_fofile + "\" + HidNo.Value.ToString() + ".pdf";

                        #endregion
                    }
                }
            }

            #region For Generate Multiple Pdf..!!
            if (Multi_listfile != "")
            {
                String[] Multifiles = Multi_listfile.Split(',');
                string DestinationFile = Server.MapPath("PDFRNew") + "\Multiple.Pdf";
                MergeFiles(DestinationFile, Multifiles);

                Response.ContentType = "pdf";
                Response.AddHeader("Content-Disposition", "attachment;filename=\"" + DestinationFile + "\"");
                Response.TransmitFile(DestinationFile);
                Response.End();
            }
            else
            {

            }
            #endregion
        }
    }

    private void MergeFiles(string DestinationFile, string[] SourceFiles)
    {
        try
        {
            int f = 0;
            /**we create a reader for a certain Document**/
            PdfReader reader = new PdfReader(SourceFiles[f]);
            /**we retrieve the total number of pages**/
            int n = reader.NumberOfPages;
            /**Console.WriteLine("There are " + n + " pages in the original file.")**/
            /**Step 1: creation of a document-object**/
            Document document = new Document(reader.GetPageSizeWithRotation(1));
            /**Step 2: we create a writer that listens to the Document**/
            PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(DestinationFile, FileMode.Create));
            /**Step 3: we open the Document**/
            document.Open();
            PdfContentByte cb = writer.DirectContent;
            PdfImportedPage page;
            int rotation;
            /**Step 4: We Add Content**/
            while (f < SourceFiles.Length)
            {
                int i = 0;
                while (i < n)
                {
                    i++;
                    document.SetPageSize(reader.GetPageSizeWithRotation(i));
                    document.NewPage();
                    page = writer.GetImportedPage(reader, i);
                    rotation = reader.GetPageRotation(i);
                    if (rotation == 90 || rotation == 270)
                    {
                        cb.AddTemplate(page, 0, -1f, 1f, 0, 0, reader.GetPageSizeWithRotation(i).Height);
                    }
                    else
                    {
                        cb.AddTemplate(page, 1f, 0, 0, 1f, 0, 0);
                    }
                    /**Console.WriteLine("Processed page " + i)**/
                }
                f++;
                if (f < SourceFiles.Length)
                {
                    reader = new PdfReader(SourceFiles[f]);
                    /**we retrieve the total number of pages**/
                    n = reader.NumberOfPages;
                    /**Console.WriteLine("There are"+n+"pages in the original file.")**/
                }
            }
            /**Step 5: we Close the Document**/
            document.Close();
        }
        catch (Exception e)
        {
            string strOb = e.Message;
        }
    }

    private bool ValidateForMultiplePDF()
    {
        bool chkList = false;

        foreach (GridViewRow gvr in grdRnew.Rows)
        {
            CheckBox Chk_One = (CheckBox)gvr.FindControl("ChkSelectOne");
            if (Chk_One.Checked == true)
            {
                chkList = true;
            }
        }
        if (chkList == false)
        {
            divStatusMsg.Style.Add("display", "");
            divStatusMsg.Attributes.Add("class", "alert alert-danger alert-dismissable");
            divStatusMsg.InnerText = "ERROR !!...Please Check At Least On CheckBox.";
            grdRnew.Focus();
            set_timeout();
            return false;
        }
        return true;
    }