ASP.net生成各种随机数字，用于优惠券、验证码等

来源：互联网发布：玛吉史密斯知乎编辑：程序博客网时间：2024/05/01 21:21

北京网站建设-恒动时空

将网上查到的资料收集整理如下：

1、利用GUID生成全球唯一标识符，长度为32位，格式如：6F9619FF-8B86-D011-B42D-00C04FC964FF。

SQLSERVER本身可以生成，ASP.NET也可以生成。

最简单的如：GUID guid = Guid.newguid()

2、将GUID转为哈希数，然后随机

Random rand = new Random(Guid.NewGuid().GetHashCode());

生成示例：1024588704

3、获取系统启动后经过的毫秒数，然后随机

Random rnd = new Random(Environment.TickCount);

生成示例：208439635

4、其他利用GUID生成的的方法示例：

 private long GenerateId()    {        byte[] buffer = Guid.NewGuid().ToByteArray();        return BitConverter.ToInt32(buffer, 0);    }

生成：5020365391994185848

 private string GenerateId(string flag)    {        long i = 1;        foreach (byte b in Guid.NewGuid().ToByteArray())        {            i *= ((int)b + 1);        }        return string.Format("{0:x}", i - DateTime.Now.Ticks);    }

生成：aded0a2611f8aa4a

5、两个用于生成不重复数字的类

public class RandomNum{    private static char[] constant ={            '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'        };    public static string GenerateRandom(int Length)    {        System.Text.StringBuilder newRandom = new System.Text.StringBuilder(62);        Random rd = new Random();        for (int i = 0; i < Length; i++)        {            newRandom.Append(constant[rd.Next(62)]);        }        return newRandom.ToString();    }}

生成：EV34SOG1RGCV（可控制生成位数）

/// <summary>/// 生成不重复乱码 /// </summary>public class RandomNumber{    const long MAX = 218340105584895; // ZZZZZZZZ    const long MIN = 568002355840; // 0a0000000    const int SeedQuantity = 1; // 随机质量，越大越慢，即使为1质量也不错    public static long[] getRandom(int size)    {        //先取一定倍量的随机种子，再从这些种子里面随机        long[] seed = getRandomSeeds(size * SeedQuantity);        long[] ranArr = new long[size];        Random rand = new Random();        for (int i = 0; i < size; i++)        {            int j = rand.Next(seed.Length - i);            ranArr[i] = seed[j];            seed[j] = seed[seed.Length - 1 - i];        }        return ranArr;    }    private static long[] getRandomSeeds(int size)    {        long[] ranArr = new long[size];        for (int i = 0; i < size; i++)        {            ranArr[i] = GetNext(i);        }        Array.Sort(ranArr); // 排序        List<int> seedRepeatPosition = new List<int>();        // 遍历一遍将重复的记录下来        long last = 0;        for (int i = 0; i < ranArr.Length; i++)        {            if (ranArr[i] == last)            {                ranArr[i] = 0;                seedRepeatPosition.Add(i);            }            else                last = ranArr[i];        }        Array.Sort(ranArr); // 排序        // 将重复的重新处理为不重复的        List<long> newseedList = new List<long>();        long newseed;        for (int i = 0; i < seedRepeatPosition.Count; i++)        {            do            {                newseed = GetNext(i);            } while (Array.BinarySearch(ranArr, newseed) > -1 || newseedList.Contains(newseed));            newseedList.Add(newseed);            ranArr[seedRepeatPosition[i]] = newseed;        }        return ranArr;    }    private static long GetNext(int seed)    {        int initSeed = (int)(DateTime.Now.Ticks - seed * 10000);        Random ran = new Random(initSeed);        double d;        long ret;        do        {            d = ran.NextDouble();            ret = Convert.ToInt64(d * (Math.Pow(10, 15)));        }        while (ret <= MIN || ret > MAX);        return ret;    }}

生成示例：217654655788864

6、其它

还可以利用当前时间的Ticks属性来获取不重复的数字，

如：DateTime.Now.Ticks

生成示例：634903854555468750

或者利用MD5

7.取时间戳生成随即数生成10位流水号

/// <summary>/// 取时间戳生成随即数生成10位流水号/// </summary>/// <returns></returns>public static UInt32 UnixStamp(){    TimeSpan ts = DateTime.Now - TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));    return Convert.ToUInt32(ts.TotalSeconds);}

8.随机数生成方法

/// <summary>/// 取随机数/// </summary>/// <param name="length"></param>/// <returns></returns>public static string BuildRandomStr(int length){    Random rand = new Random();    int num = rand.Next();    string str = num.ToString();    if (str.Length > length)    {        str = str.Substring(0, length);    }    else if (str.Length < length)    {        int n = length - str.Length;        while (n > 0)        {            str.Insert(0, "0");            n--;        }    }    return str;}

9.C# 生成一个时间戳

/// 获取时间戳  /// </summary>  /// <returns></returns>  public static string GetTimeStamp()  {      TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);      return Convert.ToInt64(ts.TotalSeconds).ToString();  
}

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