Code:

    public class Form1 : System.Windows.Forms.Form
    {
        private Device device = null;
        private System.ComponentModel.Container components = null;

        public Form1()
        {
            InitializeComponent();

            this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.Opaque, true);
        }
        
        //Ovu metodu poziva nova forma u Main-u
        public void InitializeGraphics()
        {
            PresentParameters  presentParam = new PresentParameters();

            presentParam.Windowed = true;
            presentParam.SwapEffect = SwapEffect.Discard;

            device = new                                             Device(0,DeviceType.Hardware,this,CreateFlags.SoftwareVertexProcessing,presentParam);
        }

        [STAThread]
        static void Main() 
        {
            using (Form1 frm = new Form1())
            {
                frm.Show();
                frm.InitializeGraphics();
                Application.Run(frm);
            }
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            device.Clear(ClearFlags.Target,Color.CornflowerBlue,1,0);
            device.Present();

            CustomVertex.PositionColored[] verts = new CustomVertex.PositionColored[3];

            verts[0].SetPosition(new Vector3(0,1,1));
            verts[0].Color = Color.Aqua.ToArgb();

            verts[1].SetPosition(new Vector3(-1,-1,1));
            verts[1].Color = Color.Black.ToArgb();

            verts[2].SetPosition(new Vector3(1,-1,1));
            verts[2].Color = Color.Purple.ToArgb();
            
            device.BeginScene();
            device.VertexFormat = CustomVertex.PositionColored.Format;
            device.DrawUserPrimitives(PrimitiveType.TriangleList,1,verts);
            device.EndScene();

            this.Invalidate();
        }
    }