C#生成唯一值的方法汇总

喜欢ヅ旅行 2022-05-27 03:05 227阅读 0赞

# C\#生成唯一值的方法汇总 #

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  
  
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：

using System;
     using System.Collections.Generic;
     using System.Linq;
     using System.Text;
     namespace ConsoleApplication1
     {
         class Program
         {
             static void Main(string[] args)
             {
                 string _guid = GetGuid();
                 Console.WriteLine("唯一码：{0}\t长度为：{1}\n去掉连接符：{2}", _guid, _guid.Length, _guid.Replace("-", ""));
                 string uniqueIdString = GuidTo16String();
                 Console.WriteLine("唯一码：{0}\t长度为：{1}", uniqueIdString, uniqueIdString.Length);
                 long uniqueIdLong = GuidToLongID();
                 Console.WriteLine("唯一码：{0}\t长度为：{1}", uniqueIdLong, uniqueIdLong.ToString().Length);
             }
             /// <summary>
             /// 由连字符分隔的32位数字
             /// </summary>
             /// <returns></returns>
             private static string GetGuid()
             {
                 System.Guid guid = new Guid();
                 guid = Guid.NewGuid();
                 return guid.ToString();
             }
             /// <summary>  
             /// 根据GUID获取16位的唯一字符串  
             /// </summary>  
             /// <param name=\"guid\"></param>  
             /// <returns></returns>  
             public static string GuidTo16String()
             {
                 long i = 1;
                 foreach (byte b in Guid.NewGuid().ToByteArray())
                     i *= ((int)b + 1);
                 return string.Format("{0:x}", i - DateTime.Now.Ticks);
             }
             /// <summary>  
             /// 根据GUID获取19位的唯一数字序列  
             /// </summary>  
             /// <returns></returns>  
             public static long GuidToLongID()
             {
                 byte[] buffer = Guid.NewGuid().ToByteArray();
                 return BitConverter.ToInt64(buffer, 0);
             }   
         }
     }

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

using System;
     using System.Collections.Generic;
     using System.Linq;
     using System.Text;
     using System.Threading;
     namespace ConsoleApplication1
     {
         class Program
         {
             static void Main(string[] args)
             {
                 string uniqueNum = GenerateOrderNumber();
                 Console.WriteLine("唯一码：{0}\t 长度为：{1}", uniqueNum, uniqueNum.Length);
                 //测试是否会生成重复
                   Console.WriteLine("时间+RNGCryptoServiceProvider()结合生成的唯一值，如下：");
                 string _tempNum = string.Empty;
                 for (int i = 0; i < 1000; i++)
                 {
                     string uNum = GenerateOrderNumber();
                     Console.WriteLine(uNum);
                     if (string.Equals(uNum, _tempNum))
                     {
                         Console.WriteLine("上值存在重复，按Enter键继续");
                         Console.ReadKey();
                     }
                     //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
                     Thread.Sleep(300);
                     _tempNum = uNum;
                 }
             }
             /// <summary>
             /// 唯一订单号生成
             /// </summary>
             /// <returns></returns>
             public static string GenerateOrderNumber()
             {
                 string strDateTimeNumber = DateTime.Now.ToString("yyyyMMddHHmmssms");
                 string strRandomResult = NextRandom(1000, 1).ToString();
                 return strDateTimeNumber + strRandomResult;
             }
             /// <summary>
             /// 参考：msdn上的RNGCryptoServiceProvider例子
             /// </summary>
             /// <param name="numSeeds"></param>
             /// <param name="length"></param>
             /// <returns></returns>
             private static int NextRandom(int numSeeds, int length)
             {
                 // Create a byte array to hold the random value.  
                 byte[] randomNumber = new byte[length];
                 // Create a new instance of the RNGCryptoServiceProvider.  
                 System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider();
                 // Fill the array with a random value.  
                 rng.GetBytes(randomNumber);
                 // Convert the byte to an uint value to make the modulus operation easier.  
                 uint randomResult = 0x0;
                 for (int i = 0; i < length; i++)
                 {
                     randomResult |= ((uint)randomNumber[i] << ((length - 1 - i) * 8));
                 }
                 return (int)(randomResult % numSeeds) + 1;
             }
         }
     }

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：

using System;
     using System.Collections.Generic;
     using System.Linq;
     using System.Text;
     namespace ConsoleApplication1
     { 
         class Program
         {
             static void Main(string[] args)
             {
                 string uniqueText = GenerateUniqueText(8);
                 Console.WriteLine("唯一码：{0}\t 长度为：{1}", uniqueText, uniqueText.Length);
                 //测试是否会生成重复 
                   Console.WriteLine("由[0-9A-Z] + NewGuid() 结合生成的唯一值，如下：");
                 IList<string> list = new List<string>();
                 for (int i = 1; i <= 1000; i++)
                 {
                     string _uT = GenerateUniqueText(8);
                     Console.WriteLine("{0}\t{1}", list.Count, _uT);
                     if (list.Contains(_uT))
                     {
                         Console.WriteLine("{0}值存在重复", _uT);
                         Console.ReadKey();
                     }
                     list.Add(_uT);
                     //if (i % 200 == 0)
                     //{
                         //Console.WriteLine("没有重复，按Enter键往下看");
                         //Console.ReadKey();
                     //}
                 }
                 list.Clear();
             }
     
             /// <summary>
             /// 生成特定位数的唯一字符串
             /// </summary>
             /// <param name="num">特定位数</param>
             /// <returns></returns>
             public static string GenerateUniqueText(int num)
             {
                 string randomResult = string.Empty;
                 string readyStr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
                 char[] rtn = new char[num];
                 Guid gid = Guid.NewGuid();
                 var ba = gid.ToByteArray();
                 for (var i = 0; i < num; i++)
                 {
                     rtn[i] = readyStr[((ba[i] + ba[num + i]) % 35)];
                 }
                 foreach (char r in rtn)
                 {
                     randomResult += r;
                 }
                 return randomResult;
             }
         }
     }

4、用日期 用 DateTime.Now.ToString("yyyyMMddHHmmssms") + Guid.NewGuid()作种子生成随机数组合生成唯一值，代码如下：

/// <summary>
            /// 生成订单编码,20位，日期部分在二次随机数
            /// </summary>
            /// <returns></returns>
            public static string CreateOrderNo()
            {
                var strNo = DateTime.Now.ToString("yyMMddHHmmssms");
                    var iSeed = CreateRandSeed();
                    var iSeed2 = NextRandom(1000, 2);
                    iSeed = iSeed - 500 + iSeed2;
                    var rnd = new Random(iSeed);
                    var strExt = rnd.Next(1000, 10000);
                    strNo += strExt;
    
                    //再拼接2位
                    rnd = new Random(iSeed - 1);
                    strExt = rnd.Next(10, 99);
                    strNo += strExt;
                    return strNo;
            }
            /// <summary>  
            /// 参考：msdn上的RNGCryptoServiceProvider例子  
            /// </summary>  
            /// <param name="numSeeds"></param>  
            /// <param name="length"></param>  
            /// <returns></returns>  
            public static int NextRandom(int numSeeds, int length)
            {
                // Create a byte array to hold the random value.    
                byte[] randomNumber = new byte[length];
                // Create a new instance of the RNGCryptoServiceProvider.    
                System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider();
                // Fill the array with a random value.    
                rng.GetBytes(randomNumber);
                // Convert the byte to an uint value to make the modulus operation easier.    
                uint randomResult = 0x0;
                for (int i = 0; i < length; i++)
                {
                    randomResult |= ((uint)randomNumber[i] << ((length - 1 - i) * 8));
                }
                return (int)(randomResult % numSeeds) + 1;
            }  
            public static int CreateRandSeed()
            {
                var iSeed = 0;
                var guid = Guid.NewGuid().ToString();
                iSeed = guid.GetHashCode();
                return iSeed;
            }

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

三、在SQL存储过程生成GUID，代码如下：

-- =============================================
     -- Author:      JBen
     -- Create date: 2012-06-05
     -- 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
     -- =============================================
     ALTER PROCEDURE [dbo].[pro_CreateGuid] 
         @Prefix NVARCHAR(10),
         @outputV_guid NVARCHAR(40) OUTPUT
     AS
     BEGIN
         -- SET NOCOUNT ON added to prevent extra result sets from
         -- interfering with SELECT statements.
         SET NOCOUNT ON;
         -- Insert statements for procedure here
         SET @outputV_guid = @Prefix + REPLACE(CAST(NEWID() AS VARCHAR(36)),'-','')
     END

\--- end ---