.net生成随机字符串

生成随机字符串的工具类：

    /// <summary>
    /// 随机字符串工具类
    /// </summary>
    public class RandomTools
    {

        /// <summary>
        /// 随机系数
        /// </summary>
        public static int _RandIndex = 0;

        #region 获取某个区间的一个随机数
        /// <summary>
        /// 获取某个区间的一个随机数
        /// </summary>
        /// <param name="minimum">开始区间</param>
        /// <param name="maximum">结束区间</param>
        /// <param name="length">小数点的位数</param>
        /// <param name="isSleep">是否线程睡眠</param>
        /// <param name="millisecondsTimeout">线程时间</param>
        /// <returns>返回某个区间的一个随机数</returns>
        public double GetRandomNumber(double minimum, double maximum, int length, bool isSleep = false, int millisecondsTimeout = 5)
        {
            if (isSleep)
            {
                System.Threading.Thread.Sleep(millisecondsTimeout);
            }
            Random random = new Random();
            return Math.Round((random.NextDouble() * (maximum - minimum) + minimum), length);
        }
        #endregion

        #region 生成数字随机数【随机数大小有区间限制】
        /// <summary>
        /// 数字随机数
        /// </summary>
        /// <param name="minNum">随机数的最小值</param>
        /// <param name="maxNum">随机数的最大值</param>
        /// <returns>从多少到多少之间的数据 包括开始不包括结束</returns>
        public static int RndInt(int minNum, int maxNum)
        {
            if (_RandIndex >= 1000000) _RandIndex = 1;
            Random rnd = new Random(DateTime.Now.Millisecond + _RandIndex);
            _RandIndex++;
            return rnd.Next(minNum, maxNum);
        }

        public static IList<int> RndInt(int num1, int num2, int len)
        {
            IList<int> list = new List<int>();
            for (int i = 0; i < len; i++) list.Add(RndInt(num1, num2));
            return list;
        }

        public static IList<int> RndInt(int len)
        {
            IList<int> list = RndInt(0, int.MaxValue, len);
            return list;
        }
        #endregion

        #region 生成数字随机数【随机数有长度的限制】
        /// <summary>
        /// 数字随机数
        /// </summary>
        /// <param name="length">生成长度</param>
        /// <returns>返回指定长度的数字随机串</returns>
        public static string RndNum(int length)
        {
            if (_RandIndex >= 1000000) _RandIndex = 1;
            char[] arrChar = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
            StringBuilder num = new StringBuilder();
            Random rnd = new Random(DateTime.Now.Millisecond + _RandIndex);
            for (int i = 0; i < length; i++)
            {
                num.Append(arrChar[rnd.Next(0, 9)].ToString());
            }
            return num.ToString();
        }
        #endregion

        #region 生成日期随机字符串
        /// <summary>
        /// 日期随机函数
        /// </summary>
        /// <returns>返回日期随机串</returns>
        public static string RndDateStr()
        {
            return DateTime.Now.ToString("yyyyMMddHHmmssfff") + RandomTools.RndInt(1000, 9999).ToString();
        }
        public static IList<string> RndDateStr(int len)
        {
            IList<string> list = new List<string>();
            for (int i = 0; i < len; i++) list.Add(RndDateStr());
            return list;
        }

        #endregion

        #region 生成数字和字母的随机字符串
        /// <summary>
        /// 数字和字母随机数
        /// </summary>
        /// <param name="length">生成长度</param>
        /// <returns>返回指定长度的数字和字母的随机串</returns>
        public static string RndCode(int length)
        {
            if (_RandIndex >= 1000000) _RandIndex = 1;
            char[] arrChar = new char[]{
               'a','b','d','c','e','f','g','h','i','j','k','l','m','n','p','r','q','s','t','u','v','w','z','y','x',
               '0','1','2','3','4','5','6','7','8','9',
               'A','B','C','D','E','F','G','H','I','J','K','L','M','N','Q','P','R','T','S','V','U','W','X','Y','Z'};
            System.Text.StringBuilder num = new System.Text.StringBuilder();
            Random rnd = new Random(DateTime.Now.Millisecond + _RandIndex);
            for (int i = 0; i < length; i++)
            {
                num.Append(arrChar[rnd.Next(0, arrChar.Length)].ToString());
            }
            return num.ToString();
        }
        public static IList<string> RndCodeList(int len)
        {
            IList<string> list = new List<string>();
            for (int i = 0; i < len; i++) list.Add(RndCode(len));
            return list;
        }
        #endregion

        #region 生成字母的随机字符串
        /// <summary>
        /// 字母随机数
        /// </summary>
        /// <param name="length">生成长度</param>
        /// <returns>返回指定长度的字母随机数</returns>
        public static string RndLetter(int length)
        {
            if (_RandIndex >= 1000000) _RandIndex = 1;
            char[] arrChar = new char[]{
                'a','b','d','c','e','f','g','h','i','j','k','l','m','n','p','r','q','s','t','u','v','w','z','y','x',
                '_',
                'A','B','C','D','E','F','G','H','I','J','K','L','M','N','Q','P','R','T','S','V','U','W','X','Y','Z'};
            StringBuilder num = new StringBuilder();
            Random rnd = new Random(DateTime.Now.Millisecond + _RandIndex);
            for (int i = 0; i < length; i++)
            {
                num.Append(arrChar[rnd.Next(0, arrChar.Length)].ToString());
            }
            return num.ToString();
        }
        public static IList<string> RndLetterList(int len)
        {
            IList<string> list = new List<string>();
            for (int i = 0; i < len; i++) list.Add(RndLetter(len));
            return list;
        }
        #endregion

        #region GetGuid
        /// <summary>
        /// 生成GUID
        /// </summary>
        /// <returns></returns>
        public static string GetGuid()
        {
            System.Guid g = System.Guid.NewGuid();
            return g.ToString();
        }
        public static IList<string> GetGuid(int len)
        {
            IList<string> list = new List<string>();
            for (int i = 0; i < len; i++) list.Add(GetGuid());
            return list;
        }
        #endregion


    }