c# sharpziplib adding file to existing archive

Question

Hi, am trying to add a file to an existing archive using the following code. When run no errors or exceptions are shown but no files are added to the archive either. Any ideas why?

        using (FileStream fileStream = File.Open(archivePath, FileMode.Open, FileAccess.ReadWrite))
        using (ZipOutputStream zipToWrite = new ZipOutputStream(fileStream))
        {
            zipToWrite.SetLevel(9);

            using (FileStream newFileStream = File.OpenRead(sourceFiles[0]))
            {
                byte[] byteBuffer = new byte[newFileStream.Length - 1];

                newFileStream.Read(byteBuffer, 0, byteBuffer.Length);

                ZipEntry entry = new ZipEntry(sourceFiles[0]);
                zipToWrite.PutNextEntry(entry);
                zipToWrite.Write(byteBuffer, 0, byteBuffer.Length);
                zipToWrite.CloseEntry();

                zipToWrite.Close();
                zipToWrite.Finish();
            }
        }

Answer 1

I think your Finish call should be before your Close call.

Update: This looks like a known bug. It's possible it may already have been fixed - you'll need to check your SharpZipLib version to see if it incorporates any fix. If not, you can work around it by copying all files to a new archive, adding the new file, then moving the new archive to the old archive name.

Answer 2

From Codeproject someone used this code. Only difference is close and finish otherway around and the write part:

using (ZipOutputStream s = new
ZipOutputStream(File.Create(txtSaveTo.Text + "\\" +
sZipFileName + ".zip")))
{
    s.SetLevel(9); // 0-9, 9 being the highest compression

    byte[] buffer = new byte[4096];

    foreach (string file in filenames)
    {

     ZipEntry entry = new
     ZipEntry(Path.GetFileName(file));

     entry.DateTime = DateTime.Now;
     s.PutNextEntry(entry);

     using (FileStream fs = File.OpenRead(file))
     {
      int sourceBytes;
      do
      {
       sourceBytes = fs.Read(buffer, 0,
       buffer.Length);

         s.Write(buffer, 0, sourceBytes);

      } while (sourceBytes > 0);
     }
    }
    s.Finish();
    s.Close();
}

BTW:

byte[] byteBuffer = new byte[newFileStream.Length - 1];

                newFileStream.Read(byteBuffer, 0, byteBuffer.Length);

This is incorrect, the size is newFileStream.length else the Read goes wrong. You have and array and you make it for example 10-1 is 9 bytes long, from 0 to 8.

But your reading from 0 to 9...

Answer 3

In DotNetZip, adding files to an existing zip is really simple and reliable.

using (var zip = ZipFile.Read(nameOfExistingZip))
{
    zip.CompressionLevel = Ionic.Zlib.CompressionLevel.BestCompression;
    zip.AddFile(additionalFileToAdd);
    zip.Save();
}

If you want to specify a directory path for that new file, then use a different overload for AddFile().

using (var zip = ZipFile.Read(nameOfExistingZip))
{
    zip.CompressionLevel = Ionic.Zlib.CompressionLevel.BestCompression;
    zip.AddFile(additionalFileToAdd, "directory\\For\\The\\Added\\File");
    zip.Save();
}

If you want to add a set of files, use AddFiles().

using (var zip = ZipFile.Read(nameOfExistingZip))
{
    zip.CompressionLevel = Ionic.Zlib.CompressionLevel.BestCompression;
    zip.AddFiles(listOfFilesToAdd, "directory\\For\\The\\Added\\Files");
    zip.Save();
}

You don't have to worry about Close(), CloseEntry(), CommitUpdate(), Finish() or any of that other gunk.