iText FileStream overwirtes - pdf

Question

I am in the process of putting together some code that will merge pdf's based on the file name prefix. I currently have the below code that grabs the filename and doesn't merge, but overwrites. I believe my problem is the FileStream placement, but if I move it out of the current location, I can't get the filename. Any suggestions? Thanks.
static void CreateMergedPDFs()
{
string srcDir = "C:/PDFin/";
string resultPDF = "C:/PDFout/";
{
var files = System.IO.Directory.GetFiles(srcDir);
string prevFileName = null;
int i = 1;
foreach (string file in files)
{
string filename = Left(Path.GetFileName(file), 8);
using (FileStream stream = new FileStream(resultPDF + filename + ".pdf", FileMode.Create))
{
if (prevFileName == null || filename == prevFileName)
{
Document pdfDoc = new Document(PageSize.A4);
PdfCopy pdf = new PdfCopy(pdfDoc, stream);
pdfDoc.Open();
{
pdf.AddDocument(new PdfReader(file));
i++;
}
if (pdfDoc != null)
pdfDoc.Close();
Console.WriteLine("Merges done!");
}
}
}
}
}
}
}

Answer 1

The behavior you are describing is consistent with your code. You are creating the loop in an incorrect way.
Try this:
static void CreateMergedPDFs()
{
string srcDir = "C:/PDFin/";
string resultPDF = "C:/PDFout/merged.pdf";
FileStream stream = new FileStream(resultPDF, FileMode.Create);
Document pdfDoc = new Document(PageSize.A4);
PdfCopy pdf = new PdfCopy(pdfDoc, stream);
pdfDoc.Open();
var files = System.IO.Directory.GetFiles(srcDir);
foreach (string file in files)
{
pdf.AddDocument(new PdfReader(file));
}
pdfDoc.Close();
Console.WriteLine("Merges done!");
}
}
That makes more sense, doesn't it?
If you want to group files based on their prefix, you should read the answer to the question Group files in a directory based on their prefix
In the answer to this question, it is assumed that the prefix and the rest of the filename are separated by a - character. For instance 1-abc.pdf and 1-xyz.pdf have the prefix 1 whereas 2-abc.pdf and 2-xyz.pdf have the prefix 2. In your case, it's not clear how you'd determine the prefix, but it's easy to get a list of all the files, sort them and make groups of files based on whatever algorithm you want to determine the prefix.