ZipArchive in Folder

Zipper.cs

/*
Script for zipping a list of xml files
*/
private void CreateZipPackage()
{
    String zipDir = AppDomain.CurrentDomain.BaseDirectory + @"zips\";
    DirectoryInfo di = new DirectoryInfo(zipDir);
    
    foreach (var file in di.GetFiles("*.xml"))
    {
        Compress(di, file, zipDir);
    }
}

private void Compress(DirectoryInfo directorySelected, FileInfo fileName, string directoryPath)
{
    using (FileStream zipToOpen = new FileStream(directoryPath + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip", FileMode.OpenOrCreate))
    {
        using (ZipArchive archive = new ZipArchive(zipToOpen, ZipArchiveMode.Update))
        {
            ZipArchiveEntry readmeEntry = archive.CreateEntry(fileName.Name);
            
            using (StreamWriter writer = new StreamWriter(readmeEntry.Open()))
            {
                writer.Write(GetData(fileName.FullName));
            }
        }
    }
}

private string GetData(string fileName)
{
    StringBuilder sb = new StringBuilder();
    XmlWriterSettings xws = new XmlWriterSettings();
    xws.OmitXmlDeclaration = true;
    xws.Indent = true;

    using (XmlWriter xw = XmlWriter.Create(sb, xws))
    {
        XDocument doc = XDocument.Load(fileName);
        doc.WriteTo(xw);
    }

    return sb.ToString();
}