iTextSharp生成pdf分页

string filename = DateTime.Now.ToString("yyyyMMddHHmmss").ToString() + ".pdf";

float w = PageSize.A4.Width;
float h = PageSize.A4.Height;

Rectangle rect = new Rectangle(0, 0, w, 3 * h);
Document document = new Document(rect);
PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(Server.MapPath(filename), FileMode.Create));

Rectangle crop = new Rectangle(0, 2 * h, w, 3 * h);
writer.CropBoxSize = crop;

document.Open();

PdfContentByte content = writer.DirectContent;

PdfTemplate template = content.CreateTemplate(rect.Width, rect.Height);
template.SaveState();
template.SetColorFill(Color.RED);
template.Rectangle(0, 0, w, h);
template.FillStroke();
template.RestoreState();

template.SaveState();
template.SetColorFill(Color.BLUE);
template.Rectangle(0, h, w, h);
template.FillStroke();
template.RestoreState();

template.SaveState();
template.SetColorFill(Color.BLACK);
template.Rectangle(0, 2 * h, w, h/2 );
template.FillStroke();
template.RestoreState();

content.AddTemplate(template, 1, 0, 0, -1, 0, rect.Height);

crop = new Rectangle(0, h, w, 2 * h);
writer.CropBoxSize = crop;
document.NewPage();
content.AddTemplate(template, 1, 0, 0, -1, 0, rect.Height);

crop = new Rectangle(0, 0, w, h);
writer.CropBoxSize = crop;
document.NewPage();
content.AddTemplate(template, 1, 0, 0, -1, 0, rect.Height);

document.Close();