Making Lines Not Print Improved (View Viz instead of Line Color)

David makes a great observation regarding my post at https://boostyourbim.wordpress.com/2012/12/12/making-lines-not-print-with-events/

‘That all works great if the background is in fact white. What happens if you have the same situation you were showing above with a floor tile pattern? You’d see the white line.”

The code I wrote in that post was I hope good for a relatively gentle introduction to the concept of Revit API Events. But this is not what anyone wants to see when they print.

I used the approach of changing the Object Styles – Line Color to white because it offered a straightforward way to globally change the appearance of the lines in all views. A better approach that requires greater API complexity could be to turn off the visibility of the Do Not Print sub-category in each view that is being printed.

In the previous post’s code, myPrintingEvent and myPrintedEvent both had input arguments DocumentPrintingEventArgs and DocumentPrintedEventArgs that went unused. Every event has arguments like these that are used to pass data about what is happening in this event. For the printing events, this information includes the list of views to be printed and the list of views that were printed. This will be needed for the new approach of changing  category visibility for each view that is printed.

The structure of the code is the same as the previous post, but the CategoryLineColor method has been replaced with categoryVisInViews which uses View.SetVisibility(category, boolean).

public void PrintingEventRegister()
{
    // myPrintingEvent will run just BEFORE Revit prints
    this.Application.DocumentPrinting += new EventHandler<DocumentPrintingEventArgs>(myPrintingEvent);

    // myPrintedEvent will run just AFTER Revit prints
    this.Application.DocumentPrinted += new EventHandler<DocumentPrintedEventArgs>(myPrintedEvent);
}

private void myPrintingEvent(object sender, DocumentPrintingEventArgs args)
{
    // turn OFF visibility of the ""Generic Annotations - Do Not Print" subcategory in the views being printed
    categoryVisInViews(args.Document, args.GetViewElementIds(), false);
}

private void myPrintedEvent(object sender, DocumentPrintedEventArgs args)
{
    // list of views that both printed and failed to print
    List<ElementId> views = new List<ElementId>();
    views.AddRange(args.GetFailedViewElementIds());
    views.AddRange(args.GetPrintedViewElementIds());

    // turn ON visibility of the ""Generic Annotations - Do Not Print" subcategory in views that were printed & that failed to print
    categoryVisInViews(args.Document, views, true);
}

// This function takes as inputs:
// 1) The document
// 2) The list of views in which the "Do Not Print" subcategory visibility should be changed
// 3) A boolean (true or false) indicating the desired state of the category visibility 
private void categoryVisInViews(Document doc, IList<ElementId> viewList, bool visible)
{
    foreach (ElementId id in viewList)
    {
        View view = doc.GetElement(id) as View;
        // Get all categories in the document
        Categories categories = doc.Settings.Categories;

        // The "Generic Annotations" category
        Category genericAnnotations = categories.get_Item("Generic Annotations");

        // The ""Do Not Print" subcategory of the "Generic Annotations" category
        Category doNotPrint = genericAnnotations.SubCategories.get_Item("Do Not Print");

        // Create transaction with the view name & state in the transaction name
        using (Transaction t = new Transaction(doc,"Set Visibility: " + view.Name + ": " + visible))
        {            
            t.Start();
            // set the visibility of the category
            view.setVisibility(doNotPrint, visible);
            t.Commit();
        }            
    }
}