c# - iTextSharp 从字节数组列表创建 pdf

Question

我有一个 byte[] 列表，我想将其连接成一个 byte[]，这将是最终的 PDf。

在“page = copy.GetImportedPage(new PdfReader(p), i);”我收到“对象引用未设置为实例错误”。

我不知道发生了什么，我已经检查了每个对象并且没有空值。

关于这个的任何想法，或者另一段代码可以解决这个问题？!

我有这个方法:

编辑

      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;
    }

堆栈跟踪:

[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

感谢您的宝贵时间!

Answer 1

我已经弄清楚了，只是为了让每个人都能找到解决方案:这是:

    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;
    }

希望对您有所帮助!