/// <summary>
/// This is the event handler for PrintDocument.Paginate. It creates print preview pages for the app.
/// </summary>
/// <param name="sender">PrintDocument</param>
/// <param name="e">Paginate Event Arguments</param>
protected override void CreatePrintPreviewPages(object sender, PaginateEventArgs e)
{
base.CreatePrintPreviewPages(sender, e);
PrintTaskOptionDetails printDetailedOptions = PrintTaskOptionDetails.GetFromPrintTaskOptions(e.PrintTaskOptions);
PrintPageRangeOptionDetails pageRangeOption = (PrintPageRangeOptionDetails)printDetailedOptions.Options[StandardPrintTaskOptions.CustomPageRanges];
// The number of pages may have been changed, so validate the Page Ranges again
ValidatePageRangeOption(pageRangeOption);
}
/// <summary>
/// Option change event handler
/// </summary>
/// <param name="sender">PrintTaskOptionsDetails object</param>
/// <param name="args">the event arguments containing the changed option id</param>
void printDetailedOptions_OptionChanged(PrintTaskOptionDetails sender, PrintTaskOptionChangedEventArgs args)
{
string optionId = args.OptionId as string;
if (string.IsNullOrEmpty(optionId))
{
return;
}
// Handle change in Page Range Option
if (optionId == StandardPrintTaskOptions.CustomPageRanges)
{
PrintPageRangeOptionDetails pageRangeOption = (PrintPageRangeOptionDetails)sender.Options[optionId];
ValidatePageRangeOption(pageRangeOption);
}
}
/// <summary>
/// Deals with validating that the Page Ranges only contain pages that are present in the document.
///
/// This is not necessary and some apps don't do this validation. Instead, they just ignore the pages
/// that are not present in the document and simply don't print them.
/// </summary>
/// <param name="pageRangeOption">The PrintPageRangeOptionDetails option</param>
void ValidatePageRangeOption(PrintPageRangeOptionDetails pageRangeOption)
{
IList <PrintPageRange> pageRanges = ((IList <PrintPageRange>)pageRangeOption.Value).ToImmutableList();
pageRangeOption.WarningText = "";
pageRangeOption.ErrorText = "";
// An empty list means AllPages, in which case we don't need to check the ranges
if (pageRanges.Count > 0)
{
lock (printPreviewPages)
{
// Verify that the page ranges contain at least one printable page
bool containsAtLeastOnePrintablePage = false;
foreach (PrintPageRange pageRange in pageRanges)
{
if ((pageRange.FirstPageNumber <= printPreviewPages.Count) || (pageRange.LastPageNumber <= printPreviewPages.Count))
{
containsAtLeastOnePrintablePage = true;
break;
}
}
if (containsAtLeastOnePrintablePage)
{
// Warn the user in case one of the page ranges contains pages that will not printed. That way, s/he
// can fix the page numbers in case they were mistyped.
foreach (PrintPageRange pageRange in pageRanges)
{
if ((pageRange.FirstPageNumber > printPreviewPages.Count) || (pageRange.LastPageNumber > printPreviewPages.Count))
{
pageRangeOption.WarningText = "One of the ranges contains pages that are not present in the document";
break;
}
}
}
else
{
pageRangeOption.ErrorText = "Those pages are not present in the document";
}
}
}
}
