void CreatePart(Package package, string filePath, Stream sourceStream) { filePath = filePath.Replace(PackageDirectory, "").TrimStart('\\'); var uri = PackUriHelper.CreatePartUri(new Uri(Uri.EscapeDataString(filePath), UriKind.Relative)); var packagePart = package.CreatePart(uri, "application/octet", CompressionOption.Maximum); using (var stream = packagePart.GetStream()) { sourceStream.CopyTo(stream); } }