generate random numbers with no repeat in c#

Question

How can I generate random numbers with no repeat in C#. I have one array and I want to fill every room with random numbers from 0 to 9. Each room shoud have diffrent numbers

Answer 1

        ArrayList page=new ArrayList();
        int random_index;            
        random rnd = new Random();

        for (int i = 0; i < 20; i++)
        {
            do                            
            {
                random_index = rnd.Next(10);
                if (!(page.Contains(random_index)))
                                break;
            } while (page.Contains(random_index));
            page.Add(random_index);
        }