Create a SortedList using the StringComparer.InvariantCultureIgnoreCase value.
using System; using System.Collections; using System.Globalization; public class SamplesSortedList { public static void Main() { SortedList mySL4 = new SortedList(StringComparer.InvariantCultureIgnoreCase); Console.WriteLine("mySL4 (InvariantCultureIgnoreCase):"); mySL4.Add("A", "a"); mySL4.Add("B", "b"); mySL4.Add("C", "c"); try { mySL4.Add("first", "Ola!"); } catch (ArgumentException e) { Console.WriteLine(e); } PrintKeysAndValues(mySL4); } public static void PrintKeysAndValues(SortedList myList) { Console.WriteLine(" -KEY- -VALUE-"); for (int i = 0; i < myList.Count; i++) { Console.WriteLine(" {0,-6}: {1}", myList.GetKey(i), myList.GetByIndex(i)); } Console.WriteLine(); } }