public override void OnEndPage(PdfWriter writer, Document document) {
Rectangle pageSize = writer.PageSize;
float verticalPosition = writer.GetVerticalPosition(false);
PdfContentByte canvas = writer.DirectContent;
Rectangle rect = new Rectangle(0, verticalPosition, pageSize.Right, pageSize.Top);
rect.Border = Rectangle.BOX;
rect.BorderWidth = 1;
rect.BorderColor = BaseColor.BLUE;
canvas.Rectangle(rect);
}