获取随机字符串

        /// <summary>
        /// 获取随机字符串（字符串由数字和字母组成）
        /// </summary>
        /// <param name="stringLength">字符串长度</param>
        /// <returns></returns>
        static string GetRandomString(int stringLength)
        {
            StringBuilder strReturn = new StringBuilder();
            Random rd = new Random();
            while (strReturn.Length < stringLength)
            {
                char c = Convert.ToChar(rd.Next((byte)'0', (byte)'z'));

                if (char.IsDigit(c) || char.IsLower(c) || char.IsUpper(c))
                    strReturn.Append(c);
            }

            return strReturn.ToString();
 
        }



 static string GetRandomString(int stringLength)
        {
            StringBuilder strReturn = new StringBuilder();
            do
            {
                strReturn.Append(Guid.NewGuid().ToString().Replace("-",string.Empty));
            }
            while(strReturn.Length <  stringLength);

            return strReturn.ToString(0,stringLength);
        }