产生随机数

  //Leng 随机数的子长
 public string CreateRnd(int Leng)
        {
            string Ar1 = "A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z,0,1,2,3,4,5,6,7,8,9";

            string[] ListAr = Ar1.Split(',');
            Random RD = new Random();
            int rnd = 0;
            string strRnd = "";
            for (int j = 1; j < Leng; j++)
            {
                rnd = RD.Next(0, ListAr.Length);
                strRnd += ListAr[rnd];
            }
            return strRnd;
        }