PDFOne .NET
Powerful all-in-one PDF library for .NET

Compatibility

VS 2005/2008/2010/2012/2013

Home » Newsletter » July 2010

By V. Subhash

In Version v3.0.4, we have introduced a new method named AddPageBreak() in the PDFDocument class. This method behaves like the similar feature in Microsoft Word and other word-processing applications. It inserts a new page and makes it the current page for further content rendering operations. However, the method does this only when it is creating a document. When this method is called after loading an existing document, then no new page is created but the next page is made the current page and the focus of further rendering operations.

To find out how this works, create a Windows Forms project, add two buttons and use the following click-event handlers.

// Illustrates AddPageBreak() behavior in creation mode
private void button1_Click(object sender, EventArgs e) {
  PDFDocument doc = 
     new PDFDocument("your-license-key");
  doc.OpenAfterCreate = true;
  doc.MeasurementUnit = PDFMeasurementUnit.Inches;
  doc.AutoPaginate = false;
  PDFFont fontCourier = new PDFFont(StdType1Font.Courier, PDFFontStyle.Fill, 24);

  for (float i = 1, y=0.5f; i <= 40; i++) {

    doc.WriteText(i.ToString() + 
                    ". I will not litter the classroom. ", 
                  fontCourier, 1, y);
    y += 0.5f;
    if ( (i % 10 == 0) & (i < 40)) {
        // Insert a new page
        doc.AddPageBreak();
        y = 0.5f;
    }

  }

  doc.Save("imposition.pdf");
  doc.Dispose(); 
}

// Illustrates AddPageBreak() behavior in reading mode
private void button2_Click(object sender, EventArgs e) {
  PDFDocument doc = 
     new PDFDocument("your-license-key");
  doc.Load("imposition.pdf");
  doc.OpenAfterCreate = true;
  doc.MeasurementUnit = PDFMeasurementUnit.Inches;
  doc.AutoPaginate = false;
  doc.Brush.Color = Color.Red;

  PDFFont fontCourier = new PDFFont(StdType1Font.Courier, PDFFontStyle.Fill, 24);

  for (float i = 1, y = 0.5f; i <= 40; i++) {
    doc.WriteText(" Now, behave! ", fontCourier, 5.5f, y);
    y += 0.5f;
    if ((i % 10 == 0) & (i < 40)) {
      // Move to the next page
      doc.AddPageBreak();
      y = 0.5f;
    }
  }

  doc.Save("imposition_reviewed.pdf");
  doc.Dispose();
  Close();
}

When you run the application and click on the first button, it will create a PDF document like this. The method AddPageBreak() creates a new page each time it is called.

When you click the second button, new pages are not created. However, the focus simply moves to the next page and rendering operations resume from there. Thanks to this behaviour, we are able to render content where it was previously left off when the document was first created.