C#检查字符串是否包含特殊字符

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();
      }
   }
}