pdf拆分与合并

1.引用iTextSharp，用于拆分和合并pdf文件

using iTextSharp.text;
using iTextSharp.text.pdf;

2.合并pdf

 //outMergeFile是pdf文件合并后的输出路径
 //lstFile里存放要进行合并的pdf文件的路径
 public static void mergePDFFiles(string outMergeFile, List<string> lstFile)
         {

             if (!Sql.IsEmptyString(outMergeFile))
             {
                 try
                 {
                     PdfReader reader;
                     Document document = new Document();
                     PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(Server.MapPath(outMergeFile), FileMode.Create));
                     document.Open();
                     PdfContentByte cb = writer.DirectContent;
                     PdfImportedPage newPage;
                     for (int i = ; i < lstFile.Count; i++)
                     {
                         string newpath = lstFile[i];
                         reader = new PdfReader(newpath);
                         int iPageNum = reader.NumberOfPages;
                         int startPage = ;
                         int rotation;
                         while (startPage <= iPageNum)
                         {
                             document.SetPageSize(reader.GetPageSizeWithRotation(startPage));
                             document.NewPage();
                             newPage = writer.GetImportedPage(reader, startPage);
                             rotation = reader.GetPageRotation(startPage);//获取每一页pdf文件的rotation
　　　　　　　　　　　　　　　　　　//根据每一页的rotation重置宽高，否则都按首页宽高合并可能会造成信息丢失
                             if (rotation == )
                             {
                                 cb.AddTemplate(newPage, , -1f, 1f, , , reader.GetPageSizeWithRotation(startPage).Height);
                             }
                             else if (rotation == )
                             {
                                 cb.AddTemplate(newPage, -1f, , , -1f, reader.GetPageSizeWithRotation(startPage).Width, reader.GetPageSizeWithRotation(startPage).Height);
                             }
                             else if (rotation == )
                             {
                                 cb.AddTemplate(newPage, , 1f, -1f, , reader.GetPageSizeWithRotation(startPage).Width, );
                             }
                             else
                             {
                                 cb.AddTemplate(newPage, 1f, , , 1f, , );
                             }
                             startPage++;
                         }
                     }
                     document.Close();
                 }
                 catch (Exception ex)
                 {
                     outMergeFile = string.Empty;
                     SplendidError.SystemError(new StackTrace(true).GetFrame(), ex);
                 }
             }
         }

3.pdf拆分

注：              string[] sPages = sSplitText.Split(',');
                                List<int> list = new List<int>();
                                foreach (string val in sPages)
                                {
                                    list.Add(Sql.ToInteger(val));
                                }

private void SplitPdf(byte[] imageCONTENT, string sImagePath, List<int> list)
         {
             PdfReader reader = new PdfReader(imageCONTENT);
             FileStream outFileStream = new FileStream(sImagePath, FileMode.Create);
             Document destinationDoc = null;
             PdfCopy pdfCopy = null;
             destinationDoc = new Document();
             pdfCopy = new PdfCopy(destinationDoc, outFileStream);
             destinationDoc.Open();
             if (list.Count > )
             {
                 int pageArrayIndex = ;
                 while (pageArrayIndex < list.Count)
                 {
                     destinationDoc.SetPageSize(reader.GetPageSizeWithRotation(list[pageArrayIndex]));
                     destinationDoc.NewPage();
                     pdfCopy.AddPage(pdfCopy.GetImportedPage(reader, list[pageArrayIndex]));
                     pageArrayIndex++;
                 }
             }
             destinationDoc.Close();
             destinationDoc.Dispose();
             destinationDoc = null;
         }