如何合并多个pdf文件（在运行时生成）？

How to merge multiple pdf files (generated on run time) through ItextSharp then printing them.

如何通过ItextSharp合并多个pdf文件（在运行时生成），然后打印它们。

I found the following link but that method requires the pdf names considering that the pdf files stored and this is not my case .

我发现以下链接，但该方法需要pdf名称考虑到存储的pdf文件，这不是我的情况。

---

I have multiple reports i'll convert them to pdf files through this method :

我有多个报告我会通过这种方法将它们转换为pdf文件：

private void AddReportToResponse(LocalReport followsReport)
{
    string mimeType;
    string encoding;
    string extension;
    string[] streams = new string[100];
    Warning[] warnings = new Warning[100];
    byte[] pdfStream = followsReport.Render("PDF", "", out mimeType, out encoding, out extension, out streams, out warnings);
  //Response.Clear();
  //Response.ContentType = mimeType;
  //Response.AddHeader("content-disposition", "attachment; filename=Application." + extension);
  //Response.BinaryWrite(pdfStream);
  //Response.End();
}

Now i want to merge all those generated files (Bytes) in one pdf file to print it

现在我想将所有生成的文件（字节）合并到一个pdf文件中进行打印

5 个解决方案

#1

If you want to merge source documents using iText(Sharp), there are two basic situations:

如果要使用iText（Sharp）合并源文档，有两种基本情况：

1. You really want to merge the documents, acquiring the pages in their original format, transfering as much of their content and their interactive annotations as possible. In this case you should use a solution based on a member of the Pdf*Copy* family of classes.

   您确实希望合并文档，以原始格式获取页面，尽可能多地传输内容和交互式注释。在这种情况下，您应该使用基于Pdf * Copy *系列类的成员的解决方案。

2. You actually want to integrate pages from the source documents into a new document but want the new document to govern the general format and don't care for the interactive features (annotations...) in the original documents (or even want to get rid of them). In this case you should use a solution based on the PdfWriter class.

   您实际上想要将源文档中的页面集成到新文档中，但希望新文档管理一般格式并且不关心原始文档中的交互功能（注释...）（甚至想要摆脱他们）。在这种情况下，您应该使用基于PdfWriter类的解决方案。

You can find details in chapter 6 (especially section 6.4) of iText in Action — 2nd Edition. The Java sample code can be accessed here and the C#'ified versions here.

您可以在iText in Action - 第2版的第6章（特别是第6.4节）中找到详细信息。可以在此处访问Java示例代码，并在此处访问C＃的ified版本。

A simple sample using PdfCopy is Concatenate.java / Concatenate.cs. The central piece of code is:

使用PdfCopy的简单示例是Concatenate.java / Concatenate.cs。代码的核心是：

byte[] mergedPdf = null;
using (MemoryStream ms = new MemoryStream())
{
    using (Document document = new Document())
    {
        using (PdfCopy copy = new PdfCopy(document, ms))
        {
            document.Open();

            for (int i = 0; i < pdf.Count; ++i)
            {
                PdfReader reader = new PdfReader(pdf[i]);
                // loop over the pages in that document
                int n = reader.NumberOfPages;
                for (int page = 0; page < n; )
                {
                    copy.AddPage(copy.GetImportedPage(reader, ++page));
                }
            }
        }
    }
    mergedPdf = ms.ToArray();
}

Here pdf can either be defined as a List<byte[]> immediately containing the source documents (appropriate for your use case of merging intermediate in-memory documents) or as a List<String> containing the names of source document files (appropriate if you merge documents from disk).

这里pdf既可以定义为List ，也可以直接包含源文档（适合于合并中间内存文档的用例），也可以定义为包含源文档文件名的List （如果是你从磁盘合并文件）。

An overview at the end of the referenced chapter summarizes the usage of the classes mentioned:

引用章节末尾的概述总结了所提到的类的用法：

• PdfCopy: Copies pages from one or more existing PDF documents. Major downsides: PdfCopy doesn’t detect redundant content, and it fails when concatenating forms.

  PdfCopy：从一个或多个现有PDF文档复制页面。主要缺点：PdfCopy不检测冗余内容，并且在连接表单时失败。

• PdfCopyFields: Puts the fields of the different forms into one form. Can be used to avoid the problems encountered with form fields when concatenating forms using PdfCopy. Memory use can be an issue.

  PdfCopyFields：将不同形式的字段放在一个表单中。可以用来避免在使用PdfCopy连接表单时遇到表单字段遇到的问题。内存使用可能是一个问题。

• PdfSmartCopy: Copies pages from one or more existing PDF documents. PdfSmartCopy is able to detect redundant content, but it needs more memory and CPU than PdfCopy.

  PdfSmartCopy：从一个或多个现有PDF文档复制页面。 PdfSmartCopy能够检测冗余内容，但它需要比PdfCopy更多的内存和CPU。

• PdfWriter: Generates PDF documents from scratch. Can import pages from other PDF documents. The major downside is that all interactive features of the imported page (annotations, bookmarks, fields, and so forth) are lost in the process.

  PdfWriter：从头开始生成PDF文档。可以从其他PDF文档导入页面。主要缺点是导入页面的所有交互功能（注释，书签，字段等）在此过程中都会丢失。

#2

I used iTextsharp with c# to combine pdf files. This is the code I used.

我使用iTextsharp和c＃来组合pdf文件。这是我使用的代码。

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;
    }
}

#3

Here is some code I pulled out of an old project I had. It was a web application but I was using iTextSharp to merge pdf files then print them.

这是我从一个旧项目中抽出的一些代码。这是一个Web应用程序，但我使用iTextSharp合并pdf文件然后打印它们。

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;
        }
    }

I didn't write this, but made some modifications. I can't remember where I found it. After I merged the PDFs I would call this method to insert javascript to open the print dialog when the PDF is opened. If you change bSilent to true then it should print silently to their default printer.

我没有写这个，但做了一些修改。我不记得我在哪里找到它。合并PDF后，我会调用此方法插入javascript以在打开PDF时打开打印对话框。如果将bSilent更改为true，则应以静默方式打印到其默认打印机。

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;
}

Not sure how well the above code is written since I pulled it from somewhere else and I haven't worked in depth at all with iTextSharp but I do know that it did work at merging PDFs that I was generating at runtime.

不知道上面的代码是如何编写的，因为我从其他地方提取它并且我还没有深入研究iTextSharp，但我知道它确实能够合并我在运行时生成的PDF。

#4

Tested with iTextSharp-LGPL 4.1.6:

用iTextSharp-LGPL 4.1.6测试：

    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;
        }
    }

#5

To avoid the memory issues mentioned, I used file stream instead of memory stream(mentioned in ITextSharp Out of memory exception merging multiple pdf) to merge pdf files:

为了避免提到的内存问题，我使用文件流而不是内存流（在ITextSharp中提到内存异常合并多个pdf）来合并pdf文件：

        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));
                            }
                        }
                    }
                }
            }
        }