使用iTextSharp來合併PDF檔

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO; 
using System.Collections; 
using System.ComponentModel; 
using iTextSharp.text; 
using iTextSharp.text.pdf;
using System.Drawing.Printing;
using System.Drawing; 


namespace bcsPDFMerge
{
    class iTextSharp
    {
        /// <summary> 合併PDF檔(集合) </summary> 
        /// <param name="fileList">欲合併PDF檔之集合(一筆以上)</param>
        /// <param name="outMergeFile">合併後的檔名</param> 
        public void mergePDFFiles(List<string> fileList, string outMergeFile, bool print)
        {
            PdfReader reader;
            Document document = new Document();
            PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(outMergeFile, FileMode.Create));
            document.Open();
            PdfContentByte cb = writer.DirectContent;
            PdfImportedPage newPage;
            for (int i = 0; i < fileList.Count; i++)
            {
                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);
                }
            }

            if (print)
            {
                StringBuilder script = new StringBuilder();
                script.Append("this.print({bUI: true,bSilent: true,bShrinkToFit: false});");

                writer.ViewerPreferences = PdfWriter.HideMenubar | PdfWriter.HideToolbar | PdfWriter.HideWindowUI;
                writer.AddJavaScript(script.ToString());

                //PdfAction.JavaScript("myOnMessage();", writer);
                //writer.AddJavaScript("this.print(true);function myOnMessage(aMessage) {app.alert('Test',2);} var msgHandlerObject = new Object();doc.onWillPrint = myOnMessage;this.hostContainer.messageHandler = msgHandlerObject;");
            }

            document.Close();
        }

    }
}

调用函数：

 private const short PDSAVEFULL = 1;

 private void btnMerage_Click(object sender, EventArgs e)
 {
       string path = "C:\Users\Administrator\Desktop\PDFTest\newpdf2.pdf";
       iTextSharp test = new iTextSharp();
       test.mergePDFFiles(FileList,path,true);
       System.Diagnostics.Process.Start(path);
 }

 List<string> FileList = new List<string>();
 private void btnSelectFolder_Click(object sender, EventArgs e)
 {
       folderBrowserDialog.ShowDialog();
       string floderpath = folderBrowserDialog.SelectedPath;
       if (string.IsNullOrEmpty(floderpath)) { MessageBox.Show("path error"); return; }
       DirectoryInfo theFolder = new DirectoryInfo(floderpath);                 
       FileInfo[] fileInfo = theFolder.GetFiles();
       foreach (FileInfo NextFile in fileInfo)  //遍历文件      
       {
           FileList.Add(NextFile.FullName);
       }            
 }