How to: Validate and Merge PrintTickets

Article
11/03/2006

New to Windows Vista is the Print Schema that includes the flexible and extensible PrintCapabilities and PrintTicket elements. The former itemizes the capabilities of a print device and the latter specifies how the device should use those capabilities with respect to a particular sequence of documents, individual document, or individual page.

A typical sequence of tasks for an application that supports printing would be as follows.

Determine a printer's capabilities.
Configure a PrintTicket to use those capabilities.
Validate the PrintTicket.

This article shows how to do this.

Example

In the simple example below, we are interested only in whether a printer can support duplexing — two-sided printing. The major steps are as follows.

Get a PrintCapabilities object with the GetPrintCapabilities method.

Test for the presence of the capability you want. In the example below, we test the DuplexingCapability property of the PrintCapabilities object for the presence of the capability of printing on both sides of a sheet of paper with the "page turning" along the long side of the sheet. Since DuplexingCapability is a collection, we use the Contains method of ReadOnlyCollection.

Note:
This step is not strictly necessary. The MergeAndValidatePrintTicket method used below will check each request in the PrintTicket against the capabilities of the printer. If the requested capability is not supported by printer, the printer driver will substitute an alternative request in the PrintTicket returned by the method.

If the printer supports duplexing, the sample code creates a PrintTicket that asks for duplexing. But the application does not specify every possible printer setting available in the PrintTicket element. That would be wasteful of both programmer and program time. Instead, the code sets only the duplexing request and then merges this PrintTicket with an existing, fully configured and validated, PrintTicket, in this case, the user's default PrintTicket.
Accordingly, the sample calls the MergeAndValidatePrintTicket method to merge the new, minimal, PrintTicket with the user's default PrintTicket. This returns a ValidationResult that includes the new PrintTicket as one of its properties.
The sample then tests that the new PrintTicket requests duplexing. If it does, then the sample makes it the new default print ticket for the user. If step 2 above had been left out and the printer did not support duplexing along the long side, then the test would have resulted in false. (See the note above.)
The last significant step is to commit the change to the UserPrintTicket property of the PrintQueue with the Commit method.

/// <summary>
/// Changes the user-default PrintTicket setting of the specified print queue.
/// </summary>
/// <param name="queue">the printer whose user-default PrintTicket setting needs to be changed</param>
static private void ChangePrintTicketSetting(PrintQueue queue)
{
    //
    // Obtain the printer's PrintCapabilities so we can determine whether or not
    // duplexing printing is supported by the printer.
    //
    PrintCapabilities printcap = queue.GetPrintCapabilities();

    //
    // The printer's duplexing capability is returned as a read-only collection of duplexing options
    // that can be supported by the printer. If the collection returned contains the duplexing
    // option we want to set, it means the duplexing option we want to set is supported by the printer,
    // so we can make the user-default PrintTicket setting change.
    //
    if (printcap.DuplexingCapability.Contains(Duplexing.TwoSidedLongEdge))
    {
        //
        // To change the user-default PrintTicket, we can first create a delta PrintTicket with
        // the new duplexing setting.
        //
        PrintTicket deltaTicket = new PrintTicket();
        deltaTicket.Duplexing = Duplexing.TwoSidedLongEdge;

        //
        // Then merge the delta PrintTicket onto the printer's current user-default PrintTicket,
        // and validate the merged PrintTicket to get the new PrintTicket we want to set as the
        // printer's new user-default PrintTicket.
        //
        ValidationResult result = queue.MergeAndValidatePrintTicket(queue.UserPrintTicket, deltaTicket);

        //
        // The duplexing option we want to set could be constrained by other PrintTicket settings
        // or device settings. We can check the validated merged PrintTicket to see whether the
        // the validation process has kept the duplexing option we want to set unchanged.
        //
        if (result.ValidatedPrintTicket.Duplexing == Duplexing.TwoSidedLongEdge)
        {
            //
            // Set the printer's user-default PrintTicket and commit the set operation.
            //
            queue.UserPrintTicket = result.ValidatedPrintTicket;
            queue.Commit();
            Console.WriteLine("PrintTicket new duplexing setting is set on '{0}'.", queue.FullName);
        }
        else
        {
            //
            // The duplexing option we want to set has been changed by the validation process
            // when it was resolving setting constraints.
            //
            Console.WriteLine("PrintTicket new duplexing setting is constrained on '{0}'.", queue.FullName);
        }
    }
    else
    {
        //
        // If the printer doesn't support the duplexing option we want to set, skip it.
        //
        Console.WriteLine("PrintTicket new duplexing setting is not supported on '{0}'.", queue.FullName);
    }
}

So that you can quickly test this example, the remainder of it is presented below. Create a project and a namespace and then paste both the code snippets in this article into the namespace block.

/// <summary>
/// Displays the correct command line syntax to run this sample program.
/// </summary>
static private void DisplayUsage()
{
    Console.WriteLine();
    Console.WriteLine("Usage #1: printticket.exe -l \"<printer_name>\"");
    Console.WriteLine("      Run program on the specified local printer");
    Console.WriteLine();
    Console.WriteLine("      Quotation marks may be omitted if there are no spaces in printer_name.");
    Console.WriteLine();
    Console.WriteLine("Usage #2: printticket.exe -r \"\\\\<server_name>\\<printer_name>\"");
    Console.WriteLine("      Run program on the specified network printer");
    Console.WriteLine();
    Console.WriteLine("      Quotation marks may be omitted if there are no spaces in server_name or printer_name.");
    Console.WriteLine();
    Console.WriteLine("Usage #3: printticket.exe -a");
    Console.WriteLine("      Run program on all installed printers");
    Console.WriteLine();
}


[STAThread]
static public void Main(string[] args)
{
    try
    {
        if ((args.Length == 1) && (args[0] == "-a"))
        {
            //
            // Change PrintTicket setting for all local and network printer connections.
            //
            LocalPrintServer server = new LocalPrintServer();

            EnumeratedPrintQueueTypes[] queue_types = {EnumeratedPrintQueueTypes.Local,
                                                       EnumeratedPrintQueueTypes.Connections};

            //
            // Enumerate through all the printers.
            //
            foreach (PrintQueue queue in server.GetPrintQueues(queue_types))
            {
                //
                // Change the PrintTicket setting queue by queue.
                //
                ChangePrintTicketSetting(queue);
            }
        }//end if -a

        else if ((args.Length == 2) && (args[0] == "-l"))
        {
            //
            // Change PrintTicket setting only for the specified local printer.
            //
            LocalPrintServer server = new LocalPrintServer();
            PrintQueue queue = new PrintQueue(server, args[1]);
            ChangePrintTicketSetting(queue);
        }//end if -l
            
        else if ((args.Length == 2) && (args[0] == "-r"))
        {
            //
            // Change PrintTicket setting only for the specified remote printer.
            //
            String serverName = args[1].Remove(args[1].LastIndexOf(@"\"));
            String printerName = args[1].Remove(0, args[1].LastIndexOf(@"\")+1);
            PrintServer ps = new PrintServer(serverName);
            PrintQueue queue = new PrintQueue(ps, printerName);
            ChangePrintTicketSetting(queue);
         }//end if -r
       
        else
        {
            //
            // Unrecognized command line.
            // Show user the correct command line syntax to run this sample program.
            //
            DisplayUsage();
        }
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
        Console.WriteLine(e.StackTrace);

        //
        // Show inner exception information if it's provided.
        //
        if (e.InnerException != null)
        {
            Console.WriteLine("--- Inner Exception ---");
            Console.WriteLine(e.InnerException.Message);
            Console.WriteLine(e.InnerException.StackTrace);
        }
    }
    finally
    {
        Console.WriteLine("Press Return to continue...");
        Console.ReadLine();
    }
}//end Main

How to: Validate and Merge PrintTickets

Example

See Also

Reference

Concepts

Other Resources

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