一个PDF合并操作实现类，利用iTextSharp控件实现

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。

using iTextSharp.text;

using iTextSharp.text.pdf;

/// <summary>

/// pdf文件合并处理类

/// </summary>

class PDFMergeManager

{

private PdfWriter pw;

private PdfReader reader;

private Document document;

private PdfContentByte cb;

private PdfImportedPage newPage;

/// <summary>

/// 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

/// </summary>

/// <param name="sOutFiles"></param>

public PDFMergeManager(string sOutFiles)

{

document = new Document(PageSize.A3);

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？"))

{

document = null;

throw new IOException("用户取消操作");

}

pw = PdfWriter.GetInstance(document, new FileStream(sOutFiles, FileMode.Create));

document.Open();

cb = pw.DirectContent;

}

/// <summary>

/// 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

/// </summary>

/// <param name="sm"></param>

public PDFMergeManager(Stream sm)

{

document = new Document();

pw = PdfWriter.GetInstance(document, sm);

document.Open();

cb = pw.DirectContent;

}

/// <summary>

/// 合并文件

/// </summary>

/// <param name="sFiles">需要合并的文件路径名称</param>

/// <returns></returns>

public bool MergeFile(string sFiles)

{

reader = new PdfReader(sFiles);

{

int iPageNum = reader.NumberOfPages;

for (int j = 1; j <= iPageNum; j++)

{

newPage = pw.GetImportedPage(reader, j);

Rectangle r = reader.GetPageSize(j);

document.SetPageSize(r);

document.NewPage();

cb.AddTemplate(newPage, 0, 0);

}

}

reader.Close();

return true;

}

/// <summary>

/// 通过字节数据合并文件

/// </summary>

/// <param name="pdfIn">PDF字节数据</param>

/// <returns></returns>

public bool MergeFile(byte[] pdfIn)

{

reader = new PdfReader(pdfIn);

{

int iPageNum = reader.NumberOfPages;

for (int j = 1; j <= iPageNum; j++)

{

newPage = pw.GetImportedPage(reader, j);

Rectangle r = reader.GetPageSize(j);

document.SetPageSize(r);

document.NewPage();

cb.AddTemplate(newPage, 0, 0);

}

}

reader.Close();

return true;

}

/// <summary>

/// 通过PDF文件流合并文件

/// </summary>

/// <param name="pdfStream">PDF文件流</param>

/// <returns></returns>

public bool MergeFile(Stream pdfStream)

{

reader = new PdfReader(pdfStream);

{

int iPageNum = reader.NumberOfPages;

for (int j = 1; j <= iPageNum; j++)

{

newPage = pw.GetImportedPage(reader, j);

Rectangle r = reader.GetPageSize(j);

document.SetPageSize(r);

document.NewPage();

cb.AddTemplate(newPage, 0, 0);

}

}

reader.Close();

return true;

}

/// <summary>

/// 通过网络地址来合并文件

/// </summary>

/// <param name="pdfUrl">需要合并的PDF的网络路径</param>

/// <returns></returns>

public bool MergeFile(Uri pdfUrl)

{

reader = new PdfReader(pdfUrl);

{

int iPageNum = reader.NumberOfPages;

for (int j = 1; j <= iPageNum; j++)

{

newPage = pw.GetImportedPage(reader, j);

Rectangle r = reader.GetPageSize(j);

document.SetPageSize(r);

document.NewPage();

cb.AddTemplate(newPage, 0, 0);

}

}

reader.Close();

return true;

}

/// <summary>

/// 完成合并

/// </summary>

public void FinishedMerge()

{

try

{

if (reader != null)

{

reader.Close();

}

if (pw != null)

{

pw.Flush();

pw.Close();

}

if (document.IsOpen())

{

document.Close();

}

}

catch

{

}

}

}