public class CompareOnly : IEqualityComparer<string>
    {
        public int GetHashCode(string t)
        {
            return t.GetHashCode();
        }

        public bool Equals(string x, string y)
        {
            return x.Trim().ToUpper() == y.Trim().ToUpper();
        }
    }

    class Program
    {

        static void Main(string[] args)
        {
            string[] s = new string[] { "abc", "def", "iLoVeU" };
            CompareOnly co = new CompareOnly();
            bool r = s.Contains("iloveu", co);
            Console.WriteLine(r.ToString());
            Console.ReadKey();
        }
    }