WPF rectangle - round just top corners

Question

How can I have just the top corners rounded for a WPF rectangle?

I created a border and set the CornerRadius property and inside the border I\'ve added my

Answer 1

Good example how its possible to do OnRender with DrawingContext:

   /// 

    /// Draws a rounded rectangle with four individual corner radius
    /// 
    public static void DrawRoundedRectangle(this DrawingContext dc, Brush brush,
        Pen pen, Rect rect, CornerRadius cornerRadius)
    {
        var geometry = new StreamGeometry();
        using (var context = geometry.Open())
        {
            bool isStroked = pen != null;
            const bool isSmoothJoin = true;

            context.BeginFigure(rect.TopLeft + new Vector(0, cornerRadius.TopLeft), brush != null, true);
            context.ArcTo(new Point(rect.TopLeft.X + cornerRadius.TopLeft, rect.TopLeft.Y), 
                new Size(cornerRadius.TopLeft, cornerRadius.TopLeft),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);
            context.LineTo(rect.TopRight - new Vector(cornerRadius.TopRight, 0), isStroked, isSmoothJoin);
            context.ArcTo(new Point(rect.TopRight.X, rect.TopRight.Y + cornerRadius.TopRight), 
                new Size(cornerRadius.TopRight, cornerRadius.TopRight),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);
            context.LineTo(rect.BottomRight - new Vector(0, cornerRadius.BottomRight), isStroked, isSmoothJoin);
            context.ArcTo(new Point(rect.BottomRight.X - cornerRadius.BottomRight, rect.BottomRight.Y), 
                new Size(cornerRadius.BottomRight, cornerRadius.BottomRight),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);
            context.LineTo(rect.BottomLeft + new Vector(cornerRadius.BottomLeft, 0), isStroked, isSmoothJoin);
            context.ArcTo(new Point(rect.BottomLeft.X, rect.BottomLeft.Y - cornerRadius.BottomLeft), 
                new Size(cornerRadius.BottomLeft, cornerRadius.BottomLeft),
                90, false, SweepDirection.Clockwise, isStroked, isSmoothJoin);

            context.Close();
        }
        dc.DrawGeometry(brush, pen, geometry);
    }

Information from: http://wpftutorial.net/DrawRoundedRectangle.html