C#生成随机字符串的方法2(可以用来生成主键) -----重复率极低

使用RNGCryptoServiceProvider 做种，可以在一秒内产生的随机数重复率非常的低，对于以往使用时间做种的方法是个升级，代码如下： using System; using System.Security.Cryptography; namespace ArLi.CommonPrj { /// <summary> /// 随机密码 /// </summary> public sealed class RandomStr { public const string myVersion = "1.2"; /******** * Const and Function * ********/ private static readonly int defaultLength = 8; private static int GetNewSeed(){ byte[] rndBytes = new byte[4]; RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); rng.GetBytes(rndBytes); return BitConverter.ToInt32(rndBytes,0); } /******** * getRndCode of all char . * ********/ private static string BuildRndCodeAll(int strLen) { System.Random RandomObj = new System.Random(GetNewSeed()); string buildRndCodeReturn = null; for(int i=0; i<strLen; i++) { buildRndCodeReturn += (char)RandomObj.Next(33,125); } return buildRndCodeReturn; } public static string GetRndStrOfAll() { return BuildRndCodeAll(defaultLength); } public static string GetRndStrOfAll(int LenOf) { return BuildRndCodeAll(LenOf); } /******** * getRndCode of only . * ********/ private static string sCharLow = "abcdefghijklmnopqrstuvwxyz"; private static string sCharUpp = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; private static string sNumber = "0123456789"; private static string BuildRndCodeOnly(string StrOf,int strLen) { System.Random RandomObj = new System.Random(GetNewSeed()); string buildRndCodeReturn = null; for(int i=0; i<strLen; i++) { buildRndCodeReturn += StrOf.Substring(RandomObj.Next(0,StrOf.Length-1),1); } return buildRndCodeReturn; } public static string GetRndStrOnlyFor() { return BuildRndCodeOnly(sCharLow + sNumber,defaultLength); } public static string GetRndStrOnlyFor(int LenOf) { return BuildRndCodeOnly(sCharLow + sNumber,LenOf); } public static string GetRndStrOnlyFor(bool bUseUpper,bool bUseNumber) { string strTmp = sCharLow; if (bUseUpper) strTmp += sCharUpp; if (bUseNumber) strTmp += sNumber; return BuildRndCodeOnly(strTmp,defaultLength); } public static string GetRndStrOnlyFor(int LenOf,bool bUseUpper,bool bUseNumber) { string strTmp = sCharLow; if (bUseUpper) strTmp += sCharUpp; if (bUseNumber) strTmp += sNumber; return BuildRndCodeOnly(strTmp,LenOf); } } }