C# Get random numbers

static int GetRandomNumber(int min, int max)
        {
            int rtn = 0;

            Random r = new Random();

            byte[] buffer = ().ToByteArray();
            int iSeed = BitConverter.ToInt32(buffer, 0);
            r = new Random(iSeed);

            rtn = (min, max + 1);

            return rtn;
        }