C#生成不重复的N位随机数

直接上代码：

#region 生成N位随机数

        /// <summary>

        /// 生成N位随机数

        /// </summary>

        /// <param name="N">N位随机数</param>

        /// <returns>生成的N位随机数</returns>

        public static string RandCode(int N)

        {

            char[] arrChar = new char[] { '', '', '', '', '', '', '', '', '', '' };

            StringBuilder num = new StringBuilder();

            Random rnd = new Random(Guid.NewGuid().GetHashCode());

            for (int i = ; i < N; i++)

            {

                num.Append(arrChar[rnd.Next(, arrChar.Length)].ToString());

            }

            return num.ToString();

        }

        #endregion