Creating an Epub file with a Zip library

Why not make life easier?

private void IonicZip()
{
    string sourcePath = "C:\\pulications\\";
    string fileName = "filename.epub";

    // Creating ZIP file and writing mimetype
    using (ZipOutputStream zs = new ZipOutputStream(sourcePath + fileName))
    {
        var o = zs.PutNextEntry("mimetype");
        o.CompressionLevel = CompressionLevel.None;

        byte[] mimetype = System.Text.Encoding.ASCII.GetBytes("application/epub+zip");
        zs.Write(mimetype, 0, mimetype.Length);
    }

    // Adding META-INF and OEPBS folders including files     
    using (ZipFile zip = new ZipFile(sourcePath + fileName))
    {
        zip.AddDirectory(sourcePath  + "META-INF", "META-INF");
        zip.AddDirectory(sourcePath  + "OEBPS", "OEBPS");
        zip.Save();
    }
}

If you need to control the order of the entries in the ZIP file, you can use DotNetZip and the ZipOutputStream.

You said you tried DotNetZip and it (the epub validator) gave you an error complaining about the mime type thing. This is probably because you used the ZipFile type within DotNetZip. If you use ZipOutputStream, you can control the ordering of the zip entries, which is apparently important for epub (I don't know the format, just surmising).

---

EDIT

I just checked, and the epub page on Wikipedia describes how you need to format the .epub file. It says that the mimetype file must contain specific text, must be uncompressed and unencrypted, and must appear as the first file in the ZIP archive.

Using ZipOutputStream, you would do this by setting CompressionLevel = None on that particular ZipEntry - that value is not the default.

Here's some sample code:

private void Zipup()
{
    string _outputFileName = "Fargle.epub";
    using (FileStream fs = File.Open(_outputFileName, FileMode.Create, FileAccess.ReadWrite ))
    {
        using (var output= new ZipOutputStream(fs))
        {
            var e = output.PutNextEntry("mimetype");
            e.CompressionLevel = CompressionLevel.None;

            byte[] buffer= System.Text.Encoding.ASCII.GetBytes("application/epub+zip");
            output.Write(buffer,0,buffer.Length);

            output.PutNextEntry("META-INF/container.xml");
            WriteExistingFile(output, "META-INF/container.xml");
            output.PutNextEntry("OPS/");  // another directory
            output.PutNextEntry("OPS/whatever.xhtml");
            WriteExistingFile(output, "OPS/whatever.xhtml");
            // ...
        }
    }
}

private void WriteExistingFile(Stream output, string filename)
{
    using (FileStream fs = File.Open(fileName, FileMode.Read))
    {
        int n = -1;
        byte[] buffer = new byte[2048];
        while ((n = fs.Read(buffer,0,buffer.Length)) > 0)
        {
            output.Write(buffer,0,n);
        }
    }
}

See the documentation for ZipOutputStream here.