文字列に特殊文字が含まれているかどうかを確認する C# プログラム

Char.IsLetterOrDigit

string str = "Amit$#%";

str.ToCharArray();

using System;
namespace Demo {
   class myApplication {
      static void Main(string[] args) {
         string str = "Amit$#%";
         char[] one = str.ToCharArray();
         char[] two = new char[one.Length];
         int c = 0;
         for (int i = 0; i < one.Length; i++) {
            if (!Char.IsLetterOrDigit(one[i])) {
               two[c] = one[i];
               c++;
            }
         }
         Array.Resize(ref two, c);
         Console.WriteLine("Following are the special characters:");
         foreach(var items in two) {
            Console.WriteLine(items);
         }
         Console.ReadLine();
      }
   }
}

Following are the special characters:
$
#
%