一个PDF合并操作实现类，利用iTextSharp控件实现(http://www.diybl.com/course/4_webprogram/asp.net/asp_netxl/2008109/149644.html)

实现PDF文档的合并，默认使用A3纸张来合并，可以根据需要修改。

1. using  iTextSharp.text;
2. using  iTextSharp.text.pdf;
3. /// <summary>
4.      /// pdf文件合并处理类
5.      /// </summary>
6.      class  PDFMergeManager
7.     {
8.          private  PdfWriter pw;
9.          private  PdfReader reader;       
10.          private  Document document;
11.          private  PdfContentByte cb;
12.          private  PdfImportedPage newPage;
13.          /// <summary>
14.          /// 通过输出文件来构建合并管理，合并到新增文件中,合并完成后调用FinishedMerge方法
15.          /// </summary>
16.          /// <param name="sOutFiles"></param>
17.          public  PDFMergeManager( string  sOutFiles)
18.         {
19.             document =  new  Document(PageSize.A3);         
20.              if  (File.Exists(sOutFiles) && !MessageHelper.ShowQuestion( "对应的文件已经存在，文件目录:/r/n " +sOutFiles+ "/r/n是否覆盖该文件？" ))
21.             {
22.                 document =  null ;
23.                  throw   new  IOException( "用户取消操作" );                
24.             }
25.             pw = PdfWriter.GetInstance(document,  new  FileStream(sOutFiles, FileMode.Create));
26.             document.Open();
27.             cb = pw.DirectContent;
28.         }       
29.          /// <summary>
30.          /// 通过文件流来合并文件，合并到当前的可写流中，合并完成后调用FinishedMerge方法
31.          /// </summary>
32.          /// <param name="sm"></param>
33.          public  PDFMergeManager(Stream sm)
34.         {
35.             document =  new  Document();
36.             pw = PdfWriter.GetInstance(document, sm);            
37.             document.Open();
38.             cb = pw.DirectContent;
39.         }
40.          /// <summary>
41.          /// 合并文件
42.          /// </summary>
43.          /// <param name="sFiles">需要合并的文件路径名称</param>
44.          /// <returns></returns>
45.          public   bool  MergeFile( string  sFiles)
46.         {
47.             reader =  new  PdfReader(sFiles);           
48.             {
49.                  int  iPageNum = reader.NumberOfPages;
50.                  for  ( int  j = 1; j <= iPageNum; j++)
51.                 {
52.                     
53.                     newPage = pw.GetImportedPage(reader, j);
54.                     Rectangle r = reader.GetPageSize(j);
55.                     document.SetPageSize(r);
56.                     document.NewPage();
57.                     cb.AddTemplate(newPage, 0, 0);                    
58.                 }
59.                
60.             }
61.             reader.Close();            
62.              return   true ;
63.         }
64.          /// <summary>
65.          /// 通过字节数据合并文件
66.          /// </summary>
67.          /// <param name="pdfIn">PDF字节数据</param>
68.          /// <returns></returns>
69.          public   bool  MergeFile( byte [] pdfIn)
70.         {
71.             reader =  new  PdfReader(pdfIn);
72.             {
73.                  int  iPageNum = reader.NumberOfPages;
74.                  for  ( int  j = 1; j <= iPageNum; j++)
75.                 {
77.                     newPage = pw.GetImportedPage(reader, j);
78.                     Rectangle r = reader.GetPageSize(j);
79.                     document.SetPageSize(r);
80.                     document.NewPage();
81.                     cb.AddTemplate(newPage, 0, 0);
82.                 }
84.             }
85.             reader.Close();
86.              return   true ;
87.         }
88.          /// <summary>
89.          /// 通过PDF文件流合并文件
90.          /// </summary>
91.          /// <param name="pdfStream">PDF文件流</param>
92.          /// <returns></returns>
93.          public   bool  MergeFile(Stream pdfStream)
94.         {
95.             reader =  new  PdfReader(pdfStream);
96.             {
97.                  int  iPageNum = reader.NumberOfPages;
98.                  for  ( int  j = 1; j <= iPageNum; j++)
99.                 {
101.                     newPage = pw.GetImportedPage(reader, j);
102.                     Rectangle r = reader.GetPageSize(j);
103.                     document.SetPageSize(r);
104.                     document.NewPage();
105.                     cb.AddTemplate(newPage, 0, 0);
106.                 }
108.             }
109.             reader.Close();
110.              return   true ;
111. }
112.          /// <summary>
113.          /// 通过网络地址来合并文件
114.          /// </summary>
115.          /// <param name="pdfUrl">需要合并的PDF的网络路径</param>
116.          /// <returns></returns>
117.          public   bool  MergeFile(Uri pdfUrl)
118.         {
119.             reader =  new  PdfReader(pdfUrl);
120.             {
121.                  int  iPageNum = reader.NumberOfPages;
122.                  for  ( int  j = 1; j <= iPageNum; j++)
123.                 {
125.                     newPage = pw.GetImportedPage(reader, j);
126.                     Rectangle r = reader.GetPageSize(j);
127.                     document.SetPageSize(r);
128.                     document.NewPage();
129.                     cb.AddTemplate(newPage, 0, 0);
130.                 }
132.             }
133.             reader.Close();
134.              return   true ;
135.         }
136.          /// <summary>
137.          /// 完成合并
138.          /// </summary>
139.          public   void  FinishedMerge()
140.         {
141.              try
142.             {
143.                  if  (reader !=  null )
144.                 {
145.                     reader.Close();
146.                 }
147.                  if  (pw !=  null )
148.                 {
149.                     pw.Flush();
150.                     pw.Close();
151.                 }
152.                  if  (document.IsOpen())
153.                 {
154.                     document.Close();
155.                 }
156.             }
157.              catch
158.             {
160.             }
161.         }        
162.     }