How to generate many random various numbers?

using System.Security.Cryptography;
public static int RandomNumber(int maxvalue)
{
  RandomGenerator random = RandomGenerator.Create();
  byte[] r = new byte[1];
  random.GetBytes(r);
  double val = (double)r[0]/byte.MaxValue;
  int i = (int)Math.Round(val * maxvalue, 0);
  return i; 
}