Save Method (outputStream)

The ZipFile instance is written to storage - typically a zip file in a filesystem, but using this overload, the storage can be anything accessible via a writable stream - only when the caller calls Save.

Use this method to save the zip content to a stream directly. A common scenario is an ASP.NET application that dynamically generates a zip file and allows the browser to download it. The application can call Save(Response.OutputStream) to write a zipfile directly to the output stream, without creating a zip file on the disk on the ASP.NET server.

Be careful when saving a file to a non-seekable stream, including Response.OutputStream. When DotNetZip writes to a non-seekable stream, the zip archive is formatted in such a way that may not be compatible with all zip tools on all platforms. It's a perfectly legal and compliant zip file, but some people have reported problems opening files produced this way using the Mac OS archive utility.

This example saves the zipfile content into a MemoryStream, and then gets the array of bytes from that MemoryStream.

CopyC#

using (var zip = new Ionic.Zip.ZipFile())
{
    zip.CompressionLevel= Ionic.Zlib.CompressionLevel.BestCompression;
    zip.Password = "VerySecret.";
    zip.Encryption = EncryptionAlgorithm.WinZipAes128;
    zip.AddFile(sourceFileName);
    MemoryStream output = new MemoryStream();
    zip.Save(output);

    byte[] zipbytes = output.ToArray();
}

This example shows a pitfall you should avoid. DO NOT read from a stream, then try to save to the same stream. DO NOT DO THIS:

CopyC#

using (var fs = new FileSteeam(filename, FileMode.Open))
{
  using (var zip = Ionic.Zip.ZipFile.Read(inputStream))
  {
    zip.AddEntry("Name1.txt", "this is the content");
    zip.Save(inputStream);  // NO NO NO!!
  }
}

Better like this:

CopyC#

using (var zip = Ionic.Zip.ZipFile.Read(filename))
{
    zip.AddEntry("Name1.txt", "this is the content");
    zip.Save();  // YES!
}