PrintQueueCollection.GetEnumerator 方法

定义

命名空间:

System.Printing

程序集:

System.Printing.dll

返回一个对象，该对象用于实现使用 IEnumerator 关闭的泛型 PrintQueue 接口。

public:
 virtual System::Collections::Generic::IEnumerator<System::Printing::PrintQueue ^> ^ GetEnumerator();

public virtual System.Collections.Generic.IEnumerator<System.Printing.PrintQueue> GetEnumerator ();

abstract member GetEnumerator : unit -> System.Collections.Generic.IEnumerator<System.Printing.PrintQueue>
override this.GetEnumerator : unit -> System.Collections.Generic.IEnumerator<System.Printing.PrintQueue>

Public Overridable Function GetEnumerator () As IEnumerator(Of PrintQueue)

返回

IEnumerator<PrintQueue>

实现泛型 IEnumerator 的对象，该对象可以循环访问 PrintQueue 所包含的 PrintQueueCollection 对象。

实现

GetEnumerator()

示例

以下示例演示如何使用此方法测试打印机的功能，并配置打印作业以利用它们。

// ---------------------- GetPrintTicketFromPrinter -----------------------
/// <summary>
///   Returns a PrintTicket based on the current default printer.</summary>
/// <returns>
///   A PrintTicket for the current local default printer.</returns>
PrintTicket^ GetPrintTicketFromPrinter ()
{
   PrintQueue^ printQueue = nullptr;

   LocalPrintServer^ localPrintServer = gcnew LocalPrintServer();

   // Retrieving collection of local printer on user machine
   PrintQueueCollection^ localPrinterCollection = localPrintServer->GetPrintQueues();

   System::Collections::IEnumerator^ localPrinterEnumerator = localPrinterCollection->GetEnumerator();

   if (localPrinterEnumerator->MoveNext())
   {
      // Get PrintQueue from first available printer
      printQueue = ((PrintQueue^)localPrinterEnumerator->Current);
   } else
   {
      return nullptr;
   }
   // Get default PrintTicket from printer
   PrintTicket^ printTicket = printQueue->DefaultPrintTicket;

   PrintCapabilities^ printCapabilities = printQueue->GetPrintCapabilities();

   // Modify PrintTicket
   if (printCapabilities->CollationCapability->Contains(Collation::Collated))
   {
      printTicket->Collation = Collation::Collated;
   }
   if (printCapabilities->DuplexingCapability->Contains(Duplexing::TwoSidedLongEdge))
   {
      printTicket->Duplexing = Duplexing::TwoSidedLongEdge;
   }
   if (printCapabilities->StaplingCapability->Contains(Stapling::StapleDualLeft))
   {
      printTicket->Stapling = Stapling::StapleDualLeft;
   }
   return printTicket;
};// end:GetPrintTicketFromPrinter()

// ---------------------- GetPrintTicketFromPrinter -----------------------
/// <summary>
///   Returns a PrintTicket based on the current default printer.</summary>
/// <returns>
///   A PrintTicket for the current local default printer.</returns>
private PrintTicket GetPrintTicketFromPrinter()
{
    PrintQueue printQueue = null;

    LocalPrintServer localPrintServer = new LocalPrintServer();

    // Retrieving collection of local printer on user machine
    PrintQueueCollection localPrinterCollection =
        localPrintServer.GetPrintQueues();

    System.Collections.IEnumerator localPrinterEnumerator =
        localPrinterCollection.GetEnumerator();

    if (localPrinterEnumerator.MoveNext())
    {
        // Get PrintQueue from first available printer
        printQueue = (PrintQueue)localPrinterEnumerator.Current;
    }
    else
    {
        // No printer exist, return null PrintTicket
        return null;
    }

    // Get default PrintTicket from printer
    PrintTicket printTicket = printQueue.DefaultPrintTicket;

    PrintCapabilities printCapabilities = printQueue.GetPrintCapabilities();

    // Modify PrintTicket
    if (printCapabilities.CollationCapability.Contains(Collation.Collated))
    {
        printTicket.Collation = Collation.Collated;
    }

    if ( printCapabilities.DuplexingCapability.Contains(
            Duplexing.TwoSidedLongEdge) )
    {
        printTicket.Duplexing = Duplexing.TwoSidedLongEdge;
    }

    if (printCapabilities.StaplingCapability.Contains(Stapling.StapleDualLeft))
    {
        printTicket.Stapling = Stapling.StapleDualLeft;
    }

    return printTicket;
}// end:GetPrintTicketFromPrinter()

' ---------------------- GetPrintTicketFromPrinter -----------------------
''' <summary>
'''   Returns a PrintTicket based on the current default printer.</summary>
''' <returns>
'''   A PrintTicket for the current local default printer.</returns>
Private Function GetPrintTicketFromPrinter() As PrintTicket
    Dim printQueue As PrintQueue = Nothing

    Dim localPrintServer As New LocalPrintServer()

    ' Retrieving collection of local printer on user machine
    Dim localPrinterCollection As PrintQueueCollection = localPrintServer.GetPrintQueues()

    Dim localPrinterEnumerator As System.Collections.IEnumerator = localPrinterCollection.GetEnumerator()

    If localPrinterEnumerator.MoveNext() Then
        ' Get PrintQueue from first available printer
        printQueue = CType(localPrinterEnumerator.Current, PrintQueue)
    Else
        ' No printer exist, return null PrintTicket
        Return Nothing
    End If

    ' Get default PrintTicket from printer
    Dim printTicket As PrintTicket = printQueue.DefaultPrintTicket

    Dim printCapabilities As PrintCapabilities = printQueue.GetPrintCapabilities()

    ' Modify PrintTicket
    If printCapabilities.CollationCapability.Contains(Collation.Collated) Then
        printTicket.Collation = Collation.Collated
    End If

    If printCapabilities.DuplexingCapability.Contains(Duplexing.TwoSidedLongEdge) Then
        printTicket.Duplexing = Duplexing.TwoSidedLongEdge
    End If

    If printCapabilities.StaplingCapability.Contains(Stapling.StapleDualLeft) Then
        printTicket.Stapling = Stapling.StapleDualLeft
    End If

    Return printTicket
End Function ' end:GetPrintTicketFromPrinter()

注解

建议使用 foreach 语句循环访问集合的所有成员。 仅在需要自定义迭代时使用 GetEnumerator ，例如跳过其他每个成员。