private void MergePDFFiles(string[] fileList, string outMergeFile)          {              List
     
       readerList = new List
      
       ();//记录合并PDF集合              iTextSharp.text.Document document = new iTextSharp.text.Document(iTextSharp.text.PageSize.A4.Rotate());              PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(outMergeFile, FileMode.Create));              document.Open();                PdfContentByte cb = writer.DirectContent;              PdfImportedPage newPage;              for (int i = 0; i < fileList.Length; i++)              {                  if (!string.IsNullOrEmpty(fileList[i]))                  {                      PdfReader reader = new PdfReader(fileList[i]);                      int iPageNum = reader.NumberOfPages;                      for (int j = 1; j <= iPageNum; j++)                      {                          document.NewPage();                          newPage = writer.GetImportedPage(reader, j);                          cb.AddTemplate(newPage, 0, 0);                      }                      readerList.Add(reader);                  }              }              document.Close();
      
     

　　

1             foreach (var rd in readerList)  2             {  3                 rd.Dispose();  4             }

原文链接：http://blog.csdn.net/hebbers/article/details/70332015 关键点在与

PdfReader的循环释放，定义局部变量后独立释放引用并不能完全释放，需要单独循环释放。

List
    
      readerList = new List
     
      ();
     
    

foreach (var rd in readerList)               {                 rd.Dispose();               }