我有四个要合并的MemoryStream数据,然后打开pdfDocument,而不创建单个文件.
可以将它们写入文件然后合并它们但这样做会很糟糕,这也会导致一些问题,所以我想避免这种情况.
但是,我找不到将MemoryStreams与iText5 for .NET合并的方法.
现在,这是我用文件做的方式：
private static void ConcatenateDocuments()
{
var stream = new MemoryStream();
var readerFrontPage = new PdfReader(Folder + FrontPageName);
var readerDocA = new PdfReader(Folder + docA);
var readerDocB = new PdfReader(Folder + DocB);
var readerAppendix = new PdfReader(Folder + Appendix);
var pdfCopyFields = new PdfCopyFields(stream);
pdfCopyFields.AddDocument(readerFrontPage);
pdfCopyFields.AddDocument(readerDocA );
pdfCopyFields.AddDocument(readerDocB);
pdfCopyFields.AddDocument(readerAppendix);
pdfCopyFields.Close();
SavePdf(stream,FilenameReport);
}
由于我需要删除文件的使用,因此我保留了MemoryStream,因为不同的部分是从不同的资源构建的.所以我引用了这些内存流.
如何才能做到这一点？
解决方法
在这种情况下,通过将流的位置设置回0,可以修复未找到的错误PDF标题签名.因为您没有收到错误无法访问已关闭的流我假设您已经正确地将PdfWriter的CloseStream设置为false .
下面是一个完整的C#2010 WinForm应用程序,目标是iTextSharp 5.1.1.0,它在MemoryStreams中创建三个PDF并将它们组合在一起.由于我没有方便的Web服务器,我正在将它们写入磁盘.
using System;
using System.Text;
using System.Windows.Forms;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender,EventArgs e)
{
//Create three MemoryStreams
MemoryStream[] streams = { CreateDoc("Page 1"),CreateDoc("Page 2"),CreateDoc("Page 3") };
//I don't have a web server handy so I'm going to write my final MemoryStream to a byte array and then to disk
byte[] bytes;
//Create our final combined MemoryStream
using (MemoryStream finalStream = new MemoryStream())
{
//Create our copy object
PdfCopyFields copy = new PdfCopyFields(finalStream);
//Loop through each MemoryStream
foreach (MemoryStream ms in streams)
{
//Reset the position back to zero
ms.Position = 0;
//Add it to the copy object
copy.AddDocument(new PdfReader(ms));
//Clean up
ms.Dispose();
}
//Close the copy object
copy.Close();
//Get the raw bytes to save to disk
bytes = finalStream.ToArray();
}
//Write out the file to the desktop
string outputFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop),"Combined.pdf");
using (FileStream fs = new FileStream(outputFile,FileMode.Create,FileAccess.Write,FileShare.None))
{
fs.Write(bytes,bytes.Length);
}
this.Close();
}
/// <summary>
/// Helper method to create temporary documents
/// </summary>
private MemoryStream CreateDoc(string name)
{
MemoryStream ms = new MemoryStream();
using (Document doc = new Document(PageSize.LETTER))
{
using (PdfWriter writer = PdfWriter.GetInstance(doc,ms))
{
writer.CloseStream = false;
doc.Open();
doc.Add(new Paragraph(name));
doc.Close();
}
}
return ms;
}
}
}
