private void DrawLines(CGContext context)
{
context.SetDefaultLineSettings();
for (float i = 0; i <= Frame.Height; i += cellHeight)
context.AddLines(new[] { new PointF(Frame.X, Frame.Y + i), new PointF(Frame.X + Frame.Width, Frame.Y + i) });
for (float i = 0; i <= Frame.Width; i += cellWidth)
context.AddLines(new[] { new PointF(Frame.X + i, Frame.Y), new PointF(Frame.X + i, Frame.Y + Frame.Height) });
context.DrawPath(CGPathDrawingMode.Stroke);
}