要求字符串的格式是：AXXXX-XXXXX-XXXXX-XXXXX
其中X是A～Z 或者0～9中的随机字符。
下面的两个方法GetRandomStr和MakeChar都可以。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Threading;

namespace generator
{
     class Program
        {
             static void Main()
            {
                MessageBox.Show(MakeChar());
                //MessageBox.Show(GetRandomStr(5));
             }
  
             static string GetChar()
            {
                Random chars = new Random((int)DateTime.Now.Ticks);
                int RandomNum = chars.Next(0,9);
                int RandomChar = chars.Next(65,90);
   
                if (RandomNum % 4 == 0)
                    return RandomNum.ToString();
                else
                    return ((char)RandomChar).ToString();
             }
  
             static string MakeChar()
                {
                    string seed = "A";
                    for (int i = 1; i < 30; i++)
                   {
                       Thread.Sleep(i);
                       if ((i + 1) % 6 != 0)
                           seed += GetChar();
                       else
                           seed += "-";
                    }
                    return seed.Substring(0,29);
                 }
  
             static string GetRandomStr(int seed)
            {
                 const string charSeed = "ABCD" +
                     EFGHIJKLMNOPQRSTUVWXYZ0123456789";
                 Random rand = new Random(seed + DateTime.Now.Millisecond);
                 string myChar = "A";
                 for (int i = 0; i < 24; i++)
                {
                    myChar += charSeed.Substring(rand.Next(0, charSeed.Length -1), 1);
                    if ((i - 3) % 5 == 0 & i != 23)
                        myChar += "-";
                 }
                 return myChar;  
             }
         }
}

在城里 2012.05.14