How to use background images for content elements in PDF

Introduction

Every content element defined in FlowLayout API subset provided by Apitron PDF Kit .NET component can have background set using solid color or an image. Background property can be used for solid backgrounds or pattern based colors and BackgroundImage for image backgrounds. You can also use BackgroundPosition and BackgroundRepeat properties to fine tune the background tiling if needed.

Code sample

Below is the console app sample that demonstrates how to use background for Section content element:

class Program

{

    static void Main(string[] args)

    {

        // create resource manager and add image resource

        ResourceManager resourceManager = new ResourceManager();           

        resourceManager.RegisterResource(new Apitron.PDF.Kit.FixedLayout.Resources.

XObjects.Image("background","../../images/image.jpg"));

        // create document and define styles

        FlowDocument pdfDocument = new FlowDocument();

          

        // define style for section with id = imageBackground

        pdfDocument.StyleManager.RegisterStyle("section#imageBackground", new Style()

            {

                BackgroundImage = new BackgroundImage("background"),

                Width = Length.FromPercentage(100),

                Height = Length.FromPercentage(100),

            });

        // define style for textblocks with class "title"

        pdfDocument.StyleManager.RegisterStyle("textblock.title", new Style()

            {

                Color = RgbColors.White,

                Font = new Font("Arial",40),

                Margin = new Thickness(70,395,0,0),

            });

        // add section containing text block

        pdfDocument.Add(new Section(new TextBlock("Background image sample") 

          {Class = "title"})

            {

                Id = "imageBackground"

            });

            

        // save document

        using (Stream stream = File.Create("out.pdf"))

        {

            pdfDocument.Write(stream,resourceManager);

        }

        Process.Start("out.pdf");

    }

}

This code defines two styles: one for textblock and one for its container section (of course we could simply assign all properties directly to the elements not defining the styles at all). The section gets sized to page size and also gets an image background set. The textblock becomes positioned inside this section as a child content element.

Resulting PDF document looks as follows:

Pic. 1 Background image usage sample

Conclusion

You can create impressive PDF documents using simple constructs demonstrated in this example. Content elements with image background are an easy to use and expressive way to enhance the look and feel of the new or existing documents. Download Apitron PDF Kit and try it yourself.

Downloadable version of this article can be found by the following link [PDF].