test.cs

[HttpGet]
public string[] GetSVG()
{
    lock (_lock)
    {
        using (TXTextControl.ServerTextControl tx = new ServerTextControl())
        {
            tx.Create();
            tx.Load("App_Data/demo.tx", StreamType.InternalUnicodeFormat);

            // create SVGs from all pages with glyph outlines
            var svgs = CreateSVG(tx, true, 1, -1);

            // convert SVGs to Base64 strings
            for (int i = 0; i < svgs.Length; i++)
            {
                byte[] bytes = Encoding.UTF8.GetBytes(svgs[i]);
                svgs[i] = Convert.ToBase64String(bytes);
            }

            return svgs;
        }
    }
}