C#生成唯一值的方法汇总

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生成唯一值的方法很多，下面就不同环境下生成的唯一标识方法一一介绍，作为工作中的一次总结，有兴趣的可以自行测试：

一、在 .NET 中生成

1、直接用.NET Framework 提供的 Guid() 函数，此种方法使用非常广泛。GUID（全局统一标识符）是指在一台机器上生成的数字，它保证对在同一时空中的任何两台计算机都不会生成重复的 GUID 值（即保证所有机器都是唯一的）。关于GUID的介绍在此不作具体熬述，想深入了解可以自行查阅MSDN。代码如下：

 1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 namespace ConsoleApplication1 6 { 7     class Program 8     { 9         static void Main(string[] args)10         {11             string _guid = GetGuid();12             Console.WriteLine("唯一码：{0}\t长度为：{1}\n去掉连接符：{2}", _guid, _guid.Length, _guid.Replace("-", ""));13             string uniqueIdString = GuidTo16String();14             Console.WriteLine("唯一码：{0}\t长度为：{1}", uniqueIdString, uniqueIdString.Length);15             long uniqueIdLong = GuidToLongID();16             Console.WriteLine("唯一码：{0}\t长度为：{1}", uniqueIdLong, uniqueIdLong.ToString().Length);17         }18         /// <summary>19         /// 由连字符分隔的32位数字20         /// </summary>21         /// <returns></returns>22         private static string GetGuid()23         {24             System.Guid guid = new Guid();25             guid = Guid.NewGuid();26             return guid.ToString();27         }28         /// <summary>  29         /// 根据GUID获取16位的唯一字符串  30         /// </summary>  31         /// <param name=\"guid\"></param>  32         /// <returns></returns>  33         public static string GuidTo16String()34         {35             long i = 1;36             foreach (byte b in Guid.NewGuid().ToByteArray())37                 i *= ((int)b + 1);38             return string.Format("{0:x}", i - DateTime.Now.Ticks);39         }40         /// <summary>  41         /// 根据GUID获取19位的唯一数字序列  42         /// </summary>  43         /// <returns></returns>  44         public static long GuidToLongID()45         {46             byte[] buffer = Guid.NewGuid().ToByteArray();47             return BitConverter.ToInt64(buffer, 0);48         }   49     }50 }

2、用 DateTime.Now.ToString("yyyyMMddHHmmssms") 和 .NET Framework 提供的 RNGCryptoServiceProvider() 结合生成，代码如下：

 1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.Threading; 6 namespace ConsoleApplication1 7 { 8     class Program 9     {10         static void Main(string[] args)11         {12             string uniqueNum = GenerateOrderNumber();13             Console.WriteLine("唯一码：{0}\t 长度为：{1}", uniqueNum, uniqueNum.Length);14             //测试是否会生成重复15               Console.WriteLine("时间+RNGCryptoServiceProvider()结合生成的唯一值，如下：");16             string _tempNum = string.Empty;17             for (int i = 0; i < 1000; i++)18             {19                 string uNum = GenerateOrderNumber();20                 Console.WriteLine(uNum);21                 if (string.Equals(uNum, _tempNum))22                 {23                     Console.WriteLine("上值存在重复，按Enter键继续");24                     Console.ReadKey();25                 }26                 //Sleep当前线程，是为了延时，从而不产生重复值。可以把它注释掉测试看27                 Thread.Sleep(300);28                 _tempNum = uNum;29             }30         }31         /// <summary>32         /// 唯一订单号生成33         /// </summary>34         /// <returns></returns>35         public static string GenerateOrderNumber()36         {37             string strDateTimeNumber = DateTime.Now.ToString("yyyyMMddHHmmssms");38             string strRandomResult = NextRandom(1000, 1).ToString();39             return strDateTimeNumber + strRandomResult;40         }41         /// <summary>42         /// 参考：msdn上的RNGCryptoServiceProvider例子43         /// </summary>44         /// <param name="numSeeds"></param>45         /// <param name="length"></param>46         /// <returns></returns>47         private static int NextRandom(int numSeeds, int length)48         {49             // Create a byte array to hold the random value.  50             byte[] randomNumber = new byte[length];51             // Create a new instance of the RNGCryptoServiceProvider.  52             System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider();53             // Fill the array with a random value.  54             rng.GetBytes(randomNumber);55             // Convert the byte to an uint value to make the modulus operation easier.  56             uint randomResult = 0x0;57             for (int i = 0; i < length; i++)58             {59                 randomResult |= ((uint)randomNumber[i] << ((length - 1 - i) * 8));60             }61             return (int)(randomResult % numSeeds) + 1;62         }63     }64 }

3、用 [0-9A-Z] + Guid.NewGuid() 结合生成特定位数的唯一字符串，代码如下：

 1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 namespace ConsoleApplication1 6 {  7     class Program 8     { 9         static void Main(string[] args)10         {11             string uniqueText = GenerateUniqueText(8);12             Console.WriteLine("唯一码：{0}\t 长度为：{1}", uniqueText, uniqueText.Length);13             //测试是否会生成重复 14               Console.WriteLine("由[0-9A-Z] + NewGuid() 结合生成的唯一值，如下：");15             IList<string> list = new List<string>();16             for (int i = 1; i <= 1000; i++)17             {18                 string _uT = GenerateUniqueText(8);19                 Console.WriteLine("{0}\t{1}", list.Count, _uT);20                 if (list.Contains(_uT))21                 {22                     Console.WriteLine("{0}值存在重复", _uT);23                     Console.ReadKey();24                 }25                 list.Add(_uT);26                 //if (i % 200 == 0)27                 //{28                     //Console.WriteLine("没有重复，按Enter键往下看");29                     //Console.ReadKey();30                 //}31             }32             list.Clear();33         }34 35         /// <summary>36         /// 生成特定位数的唯一字符串37         /// </summary>38         /// <param name="num">特定位数</param>39         /// <returns></returns>40         public static string GenerateUniqueText(int num)41         {42             string randomResult = string.Empty;43             string readyStr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";44             char[] rtn = new char[num];45             Guid gid = Guid.NewGuid();46             var ba = gid.ToByteArray();47             for (var i = 0; i < num; i++)48             {49                 rtn[i] = readyStr[((ba[i] + ba[num + i]) % 35)];50             }51             foreach (char r in rtn)52             {53                 randomResult += r;54             }55             return randomResult;56         }57     }58 }

4、用单例模式实现，由[0-9a-z]组合生成的唯一值，此文不讨论单例模式的多种实现方式与性能问题，随便弄一种方式实现，代码如下：

Demo结构如图：

Program.cs 程序：

  1 using System;  2 using System.Collections.Generic;  3 using System.Linq;  4 using System.Text;  5 using System.Collections;  6 using System.Xml;  7 namespace ConsoleApplication4  8 {  9     class Program 10     { 11         static void Main(string[] args) 12         { 13             CreateID createID = CreateID.GetInstance(); 14             //测试是否会生成重复  15             Console.WriteLine("单例模式实现，由[0-9a-z]组合生成的唯一值，如下："); 16             IList<string> list = new List<string>(); 17             for (int i = 1; i <= 1000000000; i++) 18             { 19                 string strUniqueNum = createID.CreateUniqueID(); 20                 Console.WriteLine("{0}\t{1}", list.Count, strUniqueNum); 21                 if (list.Contains(strUniqueNum)) 22                 { 23                     Console.WriteLine("{0}值存在重复", strUniqueNum); 24                     Console.ReadKey(); 25                 } 26                 list.Add(strUniqueNum); 27                 if (i % 200 == 0) 28                 { 29                     Console.WriteLine("没有重复，按Enter键往下看"); 30                     Console.ReadKey(); 31                 } 32             } 33             list.Clear(); 34         } 35     } 36     /// <summary> 37     /// 单例模式实现 38     /// 唯一值由[0-9a-z]组合而成，且生成的每个ID不能重复 39     /// </summary> 40     public class CreateID 41     { 42         private static CreateID _instance; 43         private static readonly object syncRoot = new object(); 44         private EHashtable hashtable = new EHashtable(); 45         private string _strXMLURL = string.Empty; 46         private CreateID() 47         { 48             hashtable.Add("0", "0"); 49             hashtable.Add("1", "1"); 50             hashtable.Add("2", "2"); 51             hashtable.Add("3", "3"); 52             hashtable.Add("4", "4"); 53             hashtable.Add("5", "5"); 54             hashtable.Add("6", "6"); 55             hashtable.Add("7", "7"); 56             hashtable.Add("8", "8"); 57             hashtable.Add("9", "9"); 58             hashtable.Add("10", "a"); 59             hashtable.Add("11", "b"); 60             hashtable.Add("12", "c"); 61             hashtable.Add("13", "d"); 62             hashtable.Add("14", "e"); 63             hashtable.Add("15", "f"); 64             hashtable.Add("16", "g"); 65             hashtable.Add("17", "h"); 66             hashtable.Add("18", "i"); 67             hashtable.Add("19", "j"); 68             hashtable.Add("20", "k"); 69             hashtable.Add("21", "l"); 70             hashtable.Add("22", "m"); 71             hashtable.Add("23", "n"); 72             hashtable.Add("24", "o"); 73             hashtable.Add("25", "p"); 74             hashtable.Add("26", "q"); 75             hashtable.Add("27", "r"); 76             hashtable.Add("28", "s"); 77             hashtable.Add("29", "t"); 78             hashtable.Add("30", "u"); 79             hashtable.Add("31", "v"); 80             hashtable.Add("32", "w"); 81             hashtable.Add("33", "x"); 82             hashtable.Add("34", "y"); 83             hashtable.Add("35", "z"); 84             _strXMLURL = System.IO.Path.GetFullPath(@"..\..\") + "XMLs\\record.xml"; 85  86         } 87         public static CreateID GetInstance() 88         { 89             if (_instance == null) 90             { 91                 lock (syncRoot) 92                 { 93                     if (_instance == null) 94                     { 95                         _instance = new CreateID(); 96                     } 97                 } 98             } 99             return _instance;100         }101         /// <summary>102         /// 创建UniqueID103         /// </summary>104         /// <returns>UniqueID</returns>105         public string CreateUniqueID()106         {107             long _uniqueid = GetGuidFromXml();108             return Convert10To36(_uniqueid);109         }110         /// <summary>111         /// 获取UniqueID总记录，即获取得到的这个ID是第几个ID112         /// 更新UniqueID使用的个数，用于下次使用113         /// </summary>114         /// <returns></returns>115         private long GetGuidFromXml()116         {117             long record = 0;118             XmlDocument xmldoc = new XmlDocument();119             xmldoc.Load(_strXMLURL);120             XmlElement rootNode = xmldoc.DocumentElement;121             //此次的个数值122             record = Convert.ToInt64(rootNode["record"].InnerText);123             //此次的个数值+1 == 下次的个数值124             rootNode["record"].InnerText = Convert.ToString(record + 1);125             xmldoc.Save(_strXMLURL);126             return record;127         }128         /// <summary>129         /// 10进制转36进制130         /// </summary>131         /// <param name="intNum10">10进制数</param>132         /// <returns></returns>133         private string Convert10To36(long intNum10)134         {135             string strNum36 = string.Empty;136             long result = intNum10 / 36;137             long remain = intNum10 % 36;138             if (hashtable.ContainsKey(remain.ToString()))139                 strNum36 = hashtable[remain.ToString()].ToString() + strNum36;140             intNum10 = result;141             while (intNum10 / 36 != 0)142             {143                 result = intNum10 / 36;144                 remain = intNum10 % 36;145                 if (hashtable.ContainsKey(remain.ToString()))146                     strNum36 = hashtable[remain.ToString()].ToString() + strNum36;147                 intNum10 = result;148             }149             if (intNum10 > 0 && intNum10 < 36)150             {151                 if (hashtable.ContainsKey(intNum10.ToString()))152                     strNum36 = hashtable[intNum10.ToString()].ToString() + strNum36;153             }154             return strNum36;155         }156     }157     /// <summary>158     /// Summary description for EHashTable159     /// </summary>160     public class EHashtable : Hashtable161     {162         private ArrayList list = new ArrayList();163         public override void Add(object key, object value)164         {165             base.Add(key, value);166             list.Add(key);167         }168         public override void Clear()169         {170             base.Clear();171             list.Clear();172         }173         public override void Remove(object key)174         {175             base.Remove(key);176             list.Remove(key);177         }178         public override ICollection Keys179         {180             get181             {182                 return list;183             }184         }185     }186 }

XML：

1 <?xml version="1.0" encoding="utf-8"?>2 <root>3   <record id="record">1</record>4 </root>

二、在JS中生成GUID，类似.NET中的 Guid.NewGuid()，代码如下：

 1 function newGuid() { //方法一： 2     var guid = ""; 3     var n = (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1); 4     for (var i = 1; i <= 8; i++) { 5         guid += n; 6     } 7     return guid; 8 } 9 function newGuid() { //方法二：10     var guid = "";11     for (var i = 1; i <= 32; i++) {12         var n = Math.floor(Math.random() * 16.0).toString(16);13         guid += n;14         if ((i == 8) || (i == 12) || (i == 16) || (i == 20))15             guid += "-";16     }17     return guid;18 }

三、在SQL存储过程生成GUID，代码如下：

 1 -- ============================================= 2 -- Author:      JBen 3 -- Create date: 2012-06-05 4 -- Description: 生成唯一标识ID，公共存储过程，可设置在别的存储过程调用此存储过程传不同的前缀 5 -- ============================================= 6 ALTER PROCEDURE [dbo].[pro_CreateGuid]  7     @Prefix NVARCHAR(10), 8     @outputV_guid NVARCHAR(40) OUTPUT 9 AS10 BEGIN11     -- SET NOCOUNT ON added to prevent extra result sets from12     -- interfering with SELECT statements.13     SET NOCOUNT ON;14     -- Insert statements for procedure here15     SET @outputV_guid = @Prefix + REPLACE(CAST(NEWID() AS VARCHAR(36)),'-','')16 END

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