Convert XAML Flow Document to XPS with Style (multiple page, page size, header, margin)
XPS is a fixed document format in which pages are pre-formated to a fixed page sixe. On the opposite of the spectrum, WPF provides flow document which can be paginated dynamically in XAML viewer. To bridge the two, WPF provides features to convert a flow document to fixed document in XPS format. Actually, you can convert any WPF Visual content to XPS.
While the default conversion is very easy to use, if you want more features, you need to write some code. This acticle shows how to convert WPF flow document to multiple page XPS with page size, margin, and header.
When a flow document is loaded in WPF, it returns an IDocumentPaginatorSource object. From it, you can get its DocumentPaginator object. When you're using XpsSerializationManager to convert a loaded flow document to XPS, it accepts a DocumentPaginator object. But the little know fact is that WPF allows you to wrap a new DocumentPaginator around a DocumentPaginator to control the conversion process.
Here is our DocumentPaginator wrapper class:
public class DocumentPaginatorWrapper : DocumentPaginator
{
Size m_PageSize;
Size m_Margin;
DocumentPaginator m_Paginator;
Typeface m_Typeface;
public DocumentPaginatorWrapper(DocumentPaginator paginator, Size pageSize, Size margin)
{
m_PageSize = pageSize;
m_Margin = margin;
m_Paginator = paginator;
m_Paginator.PageSize = new Size(m_PageSize.Width - margin.Width * 2,
m_PageSize.Height - margin.Height * 2);
}
Rect Move(Rect rect)
{
if (rect.IsEmpty)
{
return rect;
}
else
{
return new Rect(rect.Left + m_Margin.Width, rect.Top + m_Margin.Height,
rect.Width, rect.Height);
}
}
public override DocumentPage GetPage(int pageNumber)
{
DocumentPage page = m_Paginator.GetPage(pageNumber);
// Create a wrapper visual for transformation and add extras
ContainerVisual newpage = new ContainerVisual();
DrawingVisual title = new DrawingVisual();
using (DrawingContext ctx = title.RenderOpen())
{
if (m_Typeface == null)
{
m_Typeface = new Typeface("Times New Roman");
}
FormattedText text = new FormattedText("Page " + (pageNumber + 1),
System.Globalization.CultureInfo.CurrentCulture, FlowDirection.LeftToRight,
m_Typeface, 14, Brushes.Black);
ctx.DrawText(text, new Point(0, -96 / 4)); // 1/4 inch above page content
}
DrawingVisual background = new DrawingVisual();
using (DrawingContext ctx = background.RenderOpen())
{
ctx.DrawRectangle(new SolidColorBrush(Color.FromRgb(240, 240, 240)), null, page.ContentBox);
}
newpage.Children.Add(background); // Scale down page and center
ContainerVisual smallerPage = new ContainerVisual();
smallerPage.Children.Add(page.Visual);
smallerPage.Transform = new MatrixTransform(0.95, 0, 0, 0.95,
0.025 * page.ContentBox.Width, 0.025 * page.ContentBox.Height);
newpage.Children.Add(smallerPage);
newpage.Children.Add(title);
newpage.Transform = new TranslateTransform(m_Margin.Width, m_Margin.Height);
return new DocumentPage(newpage, m_PageSize, Move(page.BleedBox), Move(page.ContentBox));
}
public override bool IsPageCountValid
{
get
{
return m_Paginator.IsPageCountValid;
}
}
public override int PageCount
{
get
{
return m_Paginator.PageCount;
}
}
public override Size PageSize
{
get
{
return m_Paginator.PageSize;
}
set
{
m_Paginator.PageSize = value;
}
}
public override IDocumentPaginatorSource Source
{
get
{
return m_Paginator.Source;
}
}
}
The DocumentPaginatorWrapper constructor modifies the page size of the original paginator based on required page size and margin. The new GetPage method calls the original GetPage method to get a page, then adds a header Visual, a background Visual (just to show the original page), and then move the combined Visual by top left margin. To demonstrate that you can easily transform a Visual, the original page Visual is scaled down and centered within its original box.
Here is the code calling the wrapper class to load a flow XAML document and convert to an XPS document:
public static int SaveAsXps(string fileName)
{
object doc;
FileInfo fileInfo = new FileInfo(fileName);
using (FileStream file = fileInfo.OpenRead())
{
System.Windows.Markup.ParserContext context = new System.Windows.Markup.ParserContext();
context.BaseUri = new Uri(fileInfo.FullName, UriKind.Absolute);
doc = System.Windows.Markup.XamlReader.Load(file, context);
}
if (! (doc is IDocumentPaginatorSource))
{
Console.WriteLine("DocumentPaginatorSource expected");
return -1;
}
using (Package container = Package.Open(fileName + ".xps", FileMode.Create))
{
using (XpsDocument xpsDoc = new XpsDocument(container, CompressionOption.Maximum))
{
XpsSerializationManager rsm = new XpsSerializationManager(new XpsPackagingPolicy(xpsDoc), false);
DocumentPaginator paginator = ((IDocumentPaginatorSource)doc).DocumentPaginator;
// 8 inch x 6 inch, with half inch margin
paginator = new DocumentPaginatorWrapper(paginator, new Size(768, 676), new Size(48, 48));
rsm.SaveAsXaml(paginator);
}
}
Console.WriteLine("{0} generated.", fileName + ".xps");
return 0;
}
The code above loads a flow XAML document and paginates it to 8 inch by 6 inch, with half inch margin.
Here is a sample output:
The gray background is added to illustrate margin, header, and original page. The original page is scaled down by 5% and centered in the gray box.
The sample XAML file is extracted from WPF Feature Montage sample (http://wpf.netfx3.com/files/folders/code_snippets/entry3752.aspx).
