List a = text.Select((c, i) => new { Char = c, Index = i }).GroupBy(o => o.Index / 4).Select(g => new String(g.Select(o => o.Char).ToArray())).ToList();

http://stackoverflow.com/a/1450808

Answer:Splitting a string into chunks of a certain size https://t.co/cbpQdgkgAQ

— 「เลาเองเลาไงมีไลล๋อ」#COYG ⚽ (@sornram9254) March 17, 2016