PublicClass CustomCartesianGridLineAnnotationDrawPart 
Inherits CartesianGridLineAnnotationDrawPart

    PublicSubNew(element As CartesianGridLineAnnotation, renderer As CartesianRenderer)
        MyBase.New(element, renderer)
    EndSub
PublicOverridesSub Draw()
Dim fi As FieldInfo = GetType(CartesianGridLineAnnotation).GetField("model", BindingFlags.Instance Or BindingFlags.NonPublic)
        Dim model As ChartAnnotationModel = TryCast(fi.GetValue(Me.Element), ChartAnnotationModel)
        Dim rect As RectangleF = ChartRenderer.ToRectangleF(model.LayoutSlot)

        rect.Offset(Me.ViewportOffsetX, Me.ViewportOffsetY)
        rect.Offset(New PointF(-15, 0))
        Dim graphics As Graphics = TryCast(Me.Renderer.Surface, Graphics)
        Dim radGraphics As RadGdiGraphics = New RadGdiGraphics(graphics)

        Dim path As GraphicsPath = New GraphicsPath()
        path.AddLine(rect.Location, New PointF(rect.Right, rect.Bottom))
        Dim border As BorderPrimitiveImpl = New BorderPrimitiveImpl(Me.Element, Nothing)
        border.PaintBorder(radGraphics, Nothing, path, rect)

        rect.Size = graphics.MeasureString(Me.Element.Label, Me.Element.Font)
        rect.Offset(Me.Element.PositonOffset.Width + 1, Me.Element.PositonOffset.Height + 1)

        Dim tp As TextParams = New TextParams()
        tp.font = Me.Element.Font
        tp.foreColor = Me.Element.ForeColor
        tp.paintingRectangle = rect
        tp.text = Me.Element.Label

        Dim fill As FillPrimitiveImpl = New FillPrimitiveImpl(Me.Element, Nothing)
        fill.PaintFill(radGraphics, Nothing, rect)

        radGraphics.DrawString(tp, New SizeF(rect.Height, rect.Width))
    EndSubEndClass