public partial class Form1 : Form
    {
        Dictionary<int, Action> opcodes;
        Stopwatch watch = new Stopwatch();
        Action test = null;

        public Form1()
        {
            InitializeComponent();
            opcodes = new Dictionary<int, Action>();
            CreateEntries();
        }

        void CreateEntries()
        {
            for (int i = 0; i < 512; i++)
                opcodes.Add(i, NOP);
        }

        void NOP()
        {
        }

        private void Button1Clicked(object sender, EventArgs e)
        {
            watch.Start();
            test = opcodes[511];
            watch.Stop();
            MessageBox.Show("Time elapsed: " + watch.Elapsed);
            //test = null;
        }
    }