如何验证和合并打印票证
Microsoft Windows 打印架构 包括灵活且可扩展的 PrintCapabilities 和 PrintTicket 元素。 前者对打印设备的功能进行项化，后者指定设备应如何对文档、单个文档或单个页面的特定序列使用这些功能。
支持打印的应用程序的典型任务序列如下所示。
确定打印机的功能。
配置 PrintTicket 以使用这些功能。
验证 PrintTicket。
本文介绍如何执行此操作。
例
在下面的简单示例中，我们仅对打印机是否可以支持双面打印（双面打印）感兴趣。 主要步骤如下。
使用 GetPrintCapabilities 方法获取 PrintCapabilities 对象。
测试是否存在所需的功能。 在下面的示例中，我们测试 PrintCapabilities 对象的 DuplexingCapability 属性，以便检测其是否具备双面打印的功能，其中“翻页”方向沿纸张的长边。 由于 DuplexingCapability 是一个集合，因此我们使用 ReadOnlyCollection<T>的
Contains方法。注意
此步骤并非严格必要。 下面使用的 MergeAndValidatePrintTicket 方法将检查 PrintTicket 中的每个请求，以检查打印机的功能。 如果打印机不支持所请求的功能，打印机驱动程序将在该方法返回的 PrintTicket 中使用替代请求。
如果打印机支持双面打印，示例代码将创建一个启用双面打印的PrintTicket。 但应用程序未指定 PrintTicket 元素中可用的每个可能的打印机设置。 这将浪费程序员和程序时间。 相反，代码仅设置双工请求，然后将此 PrintTicket 与现有的、完全配置和验证的、PrintTicket（在本例中为用户的默认 PrintTicket）合并。
因此，此示例调用 MergeAndValidatePrintTicket 方法，以将新的最小 PrintTicket 与用户的默认 PrintTicket合并。 这会返回一个 ValidationResult，其中包含新 PrintTicket 作为其属性之一。
然后，该示例测试新的 PrintTicket 是否请求双工通信。 如果这样做，则该示例使其成为用户的新默认打印票证。 如果以上的步骤2被省略，并且打印机不支持长边双面打印，那么测试将导致
false。 （请参阅上面的说明。最后一个重要步骤是使用 Commit 方法将更改提交到 PrintQueue 的 UserPrintTicket 属性。
/// <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);
}
}
''' <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>
Private Shared Sub ChangePrintTicketSetting(ByVal queue As PrintQueue)
'
' Obtain the printer's PrintCapabilities so we can determine whether or not
' duplexing printing is supported by the printer.
'
Dim printcap As PrintCapabilities = 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) Then
'
' To change the user-default PrintTicket, we can first create a delta PrintTicket with
' the new duplexing setting.
'
Dim deltaTicket As 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.
'
Dim result As ValidationResult = 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 Then
'
' 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)
End If
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)
End If
End Sub
因此，可以快速测试此示例，下面显示了其余部分。 创建项目和命名空间，然后将本文中的代码片段粘贴到命名空间块中。
/// <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
''' <summary>
''' Displays the correct command line syntax to run this sample program.
''' </summary>
Private Shared Sub 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()
End Sub
<STAThread>
Public Shared Sub Main(ByVal args() As String)
Try
If (args.Length = 1) AndAlso (args(0) = "-a") Then
'
' Change PrintTicket setting for all local and network printer connections.
'
Dim server As New LocalPrintServer()
Dim queue_types() As EnumeratedPrintQueueTypes = {EnumeratedPrintQueueTypes.Local, EnumeratedPrintQueueTypes.Connections}
'
' Enumerate through all the printers.
'
For Each queue As PrintQueue In server.GetPrintQueues(queue_types)
'
' Change the PrintTicket setting queue by queue.
'
ChangePrintTicketSetting(queue)
Next queue 'end if -a
ElseIf (args.Length = 2) AndAlso (args(0) = "-l") Then
'
' Change PrintTicket setting only for the specified local printer.
'
Dim server As New LocalPrintServer()
Dim queue As New PrintQueue(server, args(1))
ChangePrintTicketSetting(queue) 'end if -l
ElseIf (args.Length = 2) AndAlso (args(0) = "-r") Then
'
' Change PrintTicket setting only for the specified remote printer.
'
Dim serverName As String = args(1).Remove(args(1).LastIndexOf("\"))
Dim printerName As String = args(1).Remove(0, args(1).LastIndexOf("\")+1)
Dim ps As New PrintServer(serverName)
Dim queue As 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()
End If
Catch e As Exception
Console.WriteLine(e.Message)
Console.WriteLine(e.StackTrace)
'
' Show inner exception information if it's provided.
'
If e.InnerException IsNot Nothing Then
Console.WriteLine("--- Inner Exception ---")
Console.WriteLine(e.InnerException.Message)
Console.WriteLine(e.InnerException.StackTrace)
End If
Finally
Console.WriteLine("Press Return to continue...")
Console.ReadLine()
End Try
End Sub
