/// <summary>
/// Prepare print content and send it to the Printing Root.
/// </summary>
private void PreparePrintContent()
{
// Create and populate print page.
var printPage = Activator.CreateInstance(this.printPageType) as Page;
printPage.DataContext = this.DataContext;
// Create print template page and fill invisible textblock with empty paragraph.
// This pushes all real content into the overflow.
firstPage = new PrintPage();
firstPage.AddContent(new Paragraph());
// Move content from print page to print template - paragraph by paragraph.
var printPageRtb = printPage.Content as RichTextBlock;
while (printPageRtb.Blocks.Count > 0)
{
var paragraph = printPageRtb.Blocks.First() as Paragraph;
printPageRtb.Blocks.Remove(paragraph);
var container = paragraph.Inlines[0] as InlineUIContainer;
if (container != null)
{
// Place the paragraph in a new textblock, and measure it.
var measureRtb = new RichTextBlock();
measureRtb.Blocks.Add(paragraph);
PrintingRoot.Children.Clear();
PrintingRoot.Children.Add(measureRtb);
PrintingRoot.InvalidateMeasure();
PrintingRoot.UpdateLayout();
measureRtb.Blocks.Remove(paragraph);
// Apply line height to trigger overflow.
paragraph.LineHeight = measureRtb.ActualHeight;
}
firstPage.AddContent(paragraph);
};
// Send it to the printing root.
PrintingRoot.Children.Clear();
PrintingRoot.Children.Add(firstPage);
}
/// <summary>
/// This function creates and adds one print preview page to the internal cache of print preview
/// pages stored in printPreviewPages.
/// </summary>
/// <param name="lastRTBOAdded">Last RichTextBlockOverflow element added in the current content</param>
/// <param name="printPageDescription">Printer's page description</param>
private RichTextBlockOverflow AddOnePrintPreviewPage(RichTextBlockOverflow lastRTBOAdded, PrintPageDescription printPageDescription)
{
// XAML element that is used to represent to "printing page"
FrameworkElement page;
// The link container for text overflowing in this page
RichTextBlockOverflow textLink;
// Check if this is the first page (no previous RichTextBlockOverflow)
if (lastRTBOAdded == null)
{
// If this is the first page add the specific scenario content
page = firstPage;
}
else
{
// Flow content (text) from previous pages
page = new PrintPage(lastRTBOAdded);
// Remove the duplicate OverflowContentTarget.
((RichTextBlock)page.FindName("textContent")).OverflowContentTarget = null;
}
// Set paper width
page.Width = printPageDescription.PageSize.Width;
page.Height = printPageDescription.PageSize.Height;
Grid printableArea = (Grid)page.FindName("printableArea");
// Get the margins size
// If the ImageableRect is smaller than the app provided margins use the ImageableRect
double marginWidth = Math.Max(printPageDescription.PageSize.Width - printPageDescription.ImageableRect.Width, printPageDescription.PageSize.Width * HorizontalPrintMargin * 2);
double marginHeight = Math.Max(printPageDescription.PageSize.Height - printPageDescription.ImageableRect.Height, printPageDescription.PageSize.Height * VerticalPrintMargin * 2);
// Set-up "printable area" on the "paper"
printableArea.Width = page.Width - marginWidth;
printableArea.Height = page.Height - marginHeight;
// Add the (newly created) page to the printing root which is part of the visual tree and force it to go
// through layout so that the linked containers correctly distribute the content inside them.
PrintingRoot.Children.Add(page);
PrintingRoot.InvalidateMeasure();
PrintingRoot.UpdateLayout();
// Find the last text container and see if the content is overflowing
textLink = (RichTextBlockOverflow)page.FindName("continuationPageLinkedContainer");
// Add page number
this.pageNumber += 1;
TextBlock pageNumberTextBlock = (TextBlock)page.FindName("pageNumber");
if (pageNumberTextBlock != null)
{
pageNumberTextBlock.Text = string.Format("- {0} -", this.pageNumber);
}
// Add the page to the page preview collection
printPreviewPages.Add(page);
return textLink;
}
