the folowing code shout show

a triangle . but dos not work

Code: Imports Microsoft.DirectX Imports Microsoft.DirectX.Direct3D Public Class Form1 Private dev As Direct3D.Device Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim prepar As New PresentParameters prepar.Windowed = True prepar.SwapEffect = SwapEffect.Discard dev = New Device(0, DeviceType.Hardware _ , Me, CreateFlags.SoftwareVertexProcessing _ , prepar) Me.SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.Opaque, True) End SubPrivate Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint dev.Clear(ClearFlags.Target _ , Color.Black, 1.0F, 0) dev.Present() Dim sx% = Me.Width / 1000Dim sy% = Me.Height / 700Dim vertices As CustomVertex.TransformedColored() = New CustomVertex.TransformedColored(0 To 2) {} ''create an array of verticesvertices(0).Position = New Vector4(10 * sx, 10 * sy, 0, 1) vertices(0).Color = &HFF0000FFvertices(1).Position = New Vector4(990 * sx, 10 * sy, 0, 1) vertices(1).Color = &HFF00FF00vertices(2).Position = New Vector4(500 * sx, 690 * sy, 0, 1) vertices(2).Color = &HFFFF0000dev.BeginScene() 'all drawings after this linedev.VertexFormat = CustomVertex.TransformedColored.Format dev.DrawUserPrimitives(PrimitiveType.TriangleList, 1, vertices) dev.EndScene() 'all drawings before this lineEnd Sub End Class

it shows a empty screen . what wend wrong ?