using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace GencKlavyelerCdKey
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        public static string CDKEY(int length,int bolme)
        {

            const string karakterler = "ABCDEFGHIJKLMNOPQRSTUVWXYZ012345678";

            String CDKEY = "";
            Random rasgele = new Random((int)DateTime.Now.Ticks);

            for (int i = 1; i < length+1; i++)
            {
                CDKEY += karakterler[rasgele.Next(karakterler.Length)];
                if(i%bolme==0&i<length)
                {
                    CDKEY += "-";
                }
            }

            return CDKEY;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            label1.Text = "CDKEY:  " + CDKEY(25, 5);
             
        }

        private void button1_Click(object sender, EventArgs e)
        {
            label1.Text = "CDKEY:  " + CDKEY(25, 5);
        }

    }
}

CDKEY(25, 5); de birinci parametre CDKEY in boyut ayarı,ikinci parametre kaçarlı olacağı ayarı için.

Kaynak:http://www.gencklavyeler.com/forum/k...todu-3520.html