如何生成8位无重复的随机数（数字+字母），急用在线等～

Question

各位高手，如何生成8位无重复的随机数（数字+字母）啊～希望给出代码。谢了～

Answer 1

public string ran2()
{
string s="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";
string[] sz=s.Split(',');
System.Collections.ArrayList al=new ArrayList();
for(int i=0;i<8;i++)
{
if(al.Count==0)
{
System.Random rd=new Random();
int a=rd.Next(0,35);
al.Add(a);
}
else
{
int c=0;
bool isonly=true;

while(isonly)
{
    System.Random rd=new Random();
    int b=rd.Next(0,25);
    if(this.isone(al,b))
    {
isonly=false;
c=b;     }
}
al.Add(c);
}
}
string rand="";
for(int j=0;j<al.Count;j++)
{

     rand+=sz[Int32.Parse(al[j].ToString())];

}
return rand;
}
下面还有一个判断唯一的函数
private bool isone(System.Collections.ArrayList a,int b)
{
bool one=true;
for(int i=0;i<a.Count;i++)
{
if(a[i].ToString()==b.ToString())
{
one=false;
i=a.Count;
}
}
return one;
}

Answer 2

int b=rd.Next(0,25);
这为什么是25，新手，不明白....

Answer 3

不是16进制的，就是生成一串8位随机的字符串，这串字符是由数字+字母组成的。
buyi2004(buyi) ：我先试试你的方法吧～大伙谁还有好方法啊～

Answer 4

一个个来嘛  先 random 一个出来，标记为a1  在随机 不等就标记为a2 继续啊

Answer 5

private string CreateRandomCode(int codeCount)
        {
            char[] allCharArray = new char[] {'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','W','X','Y','Z'};
            string s = "";
            int temp = -1;            Random rand = new Random();
            for(int i = 0; i < codeCount; i++)
            {
                if(temp != -1)
                {
                    rand = new Random(i*temp*((int)DateTime.Now.Ticks));
                }
                int t = rand.Next(allCharArray.Length);
                if(temp == t)
                {
                    return CreateRandomCode(codeCount);
                }
                temp = t;
                randomCode += allCharArray[t];
            }
            string hash = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(randomCode,"md5");
            Response.Cookies.Add(new HttpCookie("ValidateCode", hash));
            return randomCode;
        }

Answer 6

以上用于生成验证码的，传入位数
倒数第二第三句用于加密后放入Cookie
楼主不需要可以去掉

Answer 7

哦，我这个不要求唯一
sorry
楼主还是用1楼的吧

Answer 8

我也来凑个热闹~~~Public Function RandomPasswd() As String        Dim strPasswd As String
        Dim intNum As Integer = 0
        Dim objRandom As Random
        Dim intLength As Integer        objRandom = New Random
        intLength = objRandom.Next(5) + 8
        For i As Integer = 0 To intLength - 1
            intNum = objRandom.Next(3)
            If intNum = 0 Then
                strPasswd += Chr(objRandom.Next(10) + 48).ToString()
            ElseIf intNum = 1 Then
                strPasswd += Chr(objRandom.Next(26) + 65).ToString()
            Else
                strPasswd += Chr(objRandom.Next(26) + 97).ToString()
            End If
        Next        Return strPasswd
    End Function

Answer 9

这是完整的你只要进去改改数字就可以生成8位的了：希望对你有用！
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;using System.Drawing.Imaging;
using System.Drawing;
using System.IO;public partial class UserControls_Gif : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string tmp = RndNum(5).ToUpper();
        this.Session["ImageV"] = tmp;
        HttpCookie a = new HttpCookie("ImageV", tmp);
        Response.Cookies.Add(a);
        this.CreateCheckCodeImage(tmp);     }    private void ValidateCode(string VNum)
    {
        Bitmap Img = null;
        Graphics g = null;
        MemoryStream ms = null;        int gheight = VNum.Length * 15;
        Img = new Bitmap(gheight, 30);
        g = Graphics.FromImage(Img);
        //背景颜色 
        g.Clear(Color.White);
        //文字字体 
        Font f = new Font("Arial Black", 11);
        //文字颜色 
        SolidBrush s = new SolidBrush(Color.Black);
        g.DrawString(VNum, f, s, 3, 3);
        ms = new MemoryStream();
        Img.Save(ms, ImageFormat.Jpeg);
        Response.ClearContent();
        Response.ContentType = "image/Jpeg";
        Response.BinaryWrite(ms.ToArray());        g.Dispose();
        Img.Dispose();
        Response.End();
    }    private string RndNum(int VcodeNum)
    {
        string Vchar = "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";
        string[] VcArray = Vchar.Split(new Char[] { ',' });
        string VNum = "";
        int temp = -1;        Random rand = new Random();        for (int i = 1; i < VcodeNum + 1; i++)
        {
            if (temp != -1)
            {
                rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));
            }            int t = rand.Next(35);
            if (temp != -1 && temp == t)
            {
                return RndNum(VcodeNum);
            }
            temp = t;
            VNum += VcArray[t];
        }
        return VNum;
    } 
    private void CreateCheckCodeImage(string checkCode)
  {
   if(checkCode == null || checkCode.Trim() == String.Empty)
    return;   System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 15.5)), 30);
   Graphics g = Graphics.FromImage(image);   try
   {
    //生成随机生成器    Random random = new Random();    //清空图片背景色    g.Clear(Color.White);    //画图片的背景噪音线    for(int i=0; i<25; i++)
    {
     int x1 = random.Next(image.Width);
     int x2 = random.Next(image.Width);
     int y1 = random.Next(image.Height);
     int y2 = random.Next(image.Height);     g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
    }    Font font = new System.Drawing.Font("Arial", 14, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
    System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
    g.DrawString(checkCode, font, brush, 2, 2);    //画图片的前景噪音点    for(int i=0; i<100; i++)
    {
     int x = random.Next(image.Width);
     int y = random.Next(image.Height);     image.SetPixel(x, y, Color.FromArgb(random.Next()));
    }    //画图片的边框线    g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);    System.IO.MemoryStream ms = new System.IO.MemoryStream();
    image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
    Response.ClearContent();
    Response.ContentType = "image/Gif";
    Response.BinaryWrite(ms.ToArray());
   }
   finally
   {
    g.Dispose();
    image.Dispose();
   }
  }
 }

Answer 10

//生成指定长度的随机字符串
static public string GenerateRandomString(int length)
{
string s = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
string reValue = string.Empty;
Random rnd = new Random(DateTime.Now.Millisecond);
while( reValue.Length < length )
{
string s1=s[rnd.Next(0,s.Length)].ToString();
if( reValue.IndexOf(s1)==-1 ) reValue += s1;
}
return reValue;
}

Answer 11

http://www.cnblogs.com/jerryhu/archive/2006/08/11/474347.html

Answer 12

string str= "";   
string[] arr={ "0","1", "2","3","4","5","6","7","8","9", "a","b","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};   
            Random rd=new Random();   
while(str.Length<8)   
{   
String temp=arr[rd.Next(0,35)];   
if (str.IndexOf(temp) == -1)   
{   
str  +=temp;   
}   
}   
Console.WriteLine(str);

Answer 13

buyi2004(buyi) 實現了每個字符串字符的不重復，短時間也和以前的隨機數也不重復。如果在加上kongwei521(蝶恋花雨)的圖片顯示就很完美了。