RandomHelper随机数辅助类

namespace Framework { using System; using System.Globalization; using System.Text; /// <summary> /// 随机数辅助类 /// </summary> public sealed class RandomHelper { private static readonly char[] RandChar = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' }; private static Random rand = new Random(unchecked((int)DateTime.Now.Ticks)); private static int seed = 1; private RandomHelper() { } /// <summary> /// 根据规则随机生成字符串 /// </summary> /// <param name="pattern">样式："?"代表一个字符，"#"代表一个一位数字，"*"代表一个字符串或一个一位数字</param> /// <returns>随机字符串</returns> public static string GetRandStringByPattern(string pattern) { if (!pattern.Contains("#") && !pattern.Contains("?") && !pattern.Contains("*")) { return pattern; } char[] nums = pattern.ToCharArray(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < nums.Length; i++) { switch (nums[i]) { case '?': nums[i] = RandChar[rand.Next(10, 62)]; break; case '#': nums[i] = RandChar[rand.Next(0, 10)]; break; case '*': nums[i] = RandChar[rand.Next(62)]; break; default: break; } sb.Append(nums[i]); } return sb.ToString(); } /// <summary> /// 生成随机的数值 /// </summary> /// <param name="min">随机数可取该下界值</param> /// <param name="max">随机数的上界</param> /// <returns>随机的数值</returns> public static int GetFormatedNumeric(int min, int max) { int num = 0; Random ro = new Random(unchecked(seed * (int)DateTime.Now.Ticks)); num = ro.Next(min, max); seed++; return num; } /// <summary> /// 获取指定长度和字符的随机字符串 /// 通过调用 Random 类的 Next() 方法，先获得一个大于或等于 0 而小于 pwdchars 长度的整数 /// 以该数作为索引值，从可用字符串中随机取字符，以指定的密码长度为循环次数 /// 依次连接取得的字符，最后即得到所需的随机密码串了。 /// </summary> /// <param name="pwdchars">随机字符串里包含的字符</param> /// <param name="pwdlen">随机字符串的长度</param> /// <returns>随机产生的字符串</returns> public static string GetRandomString(string pwdchars, int pwdlen) { StringBuilder tmpstr = new StringBuilder(); int randNum; for (int i = 0; i < pwdlen; i++) { randNum = rand.Next(pwdchars.Length); tmpstr.Append(pwdchars[randNum]); } return tmpstr.ToString(); } /// <summary> /// 获取指定长度的随机字符串 /// </summary> /// <param name="pwdlen">随机字符串的长度</param> /// <returns>随机产生的字符串</returns> public static string GetRandomString(int pwdlen) { return GetRandomString("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_*", pwdlen); } /// <summary> /// 获取指定长度的纯字母随机字符串 /// </summary> /// <param name="pwdlen">数字串长度</param> /// <returns>纯字母随机字符串</returns> public static string GetRandWord(int pwdlen) { return GetRandomString("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ", pwdlen); } /// <summary> /// 获取指定长度的纯数字随机数字串 /// </summary> /// <param name="intlong">数字串长度</param> /// <returns>纯数字随机数字串</returns> public static string GetRandomNum(int intlong) { StringBuilder w = new StringBuilder(string.Empty); for (int i = 0; i < intlong; i++) { w.Append(rand.Next(10)); } return w.ToString(); } /// <summary> /// 获取按照年月时分秒随机数生成的文件名 /// </summary> /// <returns>随机文件名</returns> public static string GetFileRndName() { return DateTime.Now.ToString("yyyyMMddHHmmss", CultureInfo.CurrentCulture) + GetRandomString("0123456789", 4); } } }