C#數組隨機生成四個隨機數

  int[] face = new int[4];
            Random ra = new Random();
            for (int i = 0; i < face.Length; i++)
            {
                int count = 0;
                face[i] = ra.Next(0,2);
                for (int j= 0; j < i; j++)
                {
                    if (face[i]==face[j])
                    {
                        count++;
                        if (count==2)
                        {
                        i--;
                        break;
                        }
                    }
                }
            }
            for (int i = 0; i < face.Length; i++)
            {
                Console.WriteLine(face[i]);
            }