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Come stampare un file XPS (WPF .NET)

  • Articolo

A volte potresti voler aggiungere un nuovo lavoro di stampa alla coda di stampa senza aprire una finestra di dialogo di stampa. A tale scopo, è possibile usare uno dei metodi PrintQueue.AddJob. Ecco come.

Nell'esempio seguente viene usato il metodo AddJob(String, String, Boolean), uno dei diversi overload del metodo AddJob, per:

  • Aggiungi un nuovo lavoro di stampa per un documento XPS (XML Paper Specification) nella coda di stampa predefinita.
  • Assegnare un nome al nuovo lavoro.
  • Specificare se il documento XPS deve essere convalidato (usando il parametro fastCopy).

Quando si usa il metodo AddJob(String, String, Boolean), il valore del parametro fastCopy è una considerazione chiave:

  • Se si imposta il parametro fastCopy su true, la convalida XPS viene ignorata e il processo di stampa eseguirà rapidamente lo spooling senza feedback sul progresso pagina per pagina.
  • Se si imposta il parametro fastCopy su false, il thread che chiama il metodo AddJob deve avere uno stato di appartamento a thread singolo , in caso contrario verrà generata un'eccezione. Per ulteriori informazioni, vedere la sezione Osservazioni per AddJob(String, String, Boolean).

Aggiungere nuovi lavori di stampa alla coda

In questo esempio, vengono aggiunti alla coda predefinita uno o più documenti XPS. Il codice farà:

  1. Usare Task.Run per evitare di bloccare il thread dell'interfaccia utente, perché non esiste una versione asincrona di AddJob.
  2. Se il valore del parametro fastCopy è false, eseguire AddJob(String, String, Boolean) in un thread con stato apartment a thread singolo.
  3. Ottieni un riferimento alla PrintQueue predefinita del LocalPrintServer.
  4. Chiamare AddJob(String, String, Boolean) sul riferimento alla coda di stampa, passando un nome del lavoro, un percorso del documento XPS e il parametro fastCopy.

Se la coda non è sospesa e la stampante funziona, un processo di stampa inizierà automaticamente la stampa quando raggiunge la parte superiore della coda di stampa.

Consiglio

Per evitare la finestra di dialogo Salva file di output come quando si aggiunge un lavoro di stampa alla coda predefinita, assicurarsi che la stampante predefinita non sia Microsoft XPS Document Writer, Microsoft Print to PDFo altre opzioni di stampa su file.

/// <summary>
/// Asyncronously, add a batch of XPS documents to the print queue using a PrintQueue.AddJob method.
/// Handle the thread apartment state required by the PrintQueue.AddJob method.
/// </summary>
/// <param name="xpsFilePaths">A collection of XPS documents.</param>
/// <param name="fastCopy">Whether to validate the XPS documents.</param>
/// <returns>Whether all documents were added to the print queue.</returns>
public static async Task<bool> BatchAddToPrintQueueAsync(IEnumerable<string> xpsFilePaths, bool fastCopy = false)
{
    bool allAdded = true;

    // Queue some work to run on the ThreadPool.
    // Wait for completion without blocking the calling thread.
    await Task.Run(() =>
    {
        if (fastCopy)
            allAdded = BatchAddToPrintQueue(xpsFilePaths, fastCopy);
        else
        {
            // Create a thread to call the PrintQueue.AddJob method.
            Thread newThread = new(() =>
            {
                allAdded = BatchAddToPrintQueue(xpsFilePaths, fastCopy);
            });

            // Set the thread to single-threaded apartment state.
            newThread.SetApartmentState(ApartmentState.STA);

            // Start the thread.
            newThread.Start();

            // Wait for thread completion. Blocks the calling thread,
            // which is a ThreadPool thread.
            newThread.Join();
        }
    });

    return allAdded;
}

/// <summary>
/// Add a batch of XPS documents to the print queue using a PrintQueue.AddJob method.
/// </summary>
/// <param name="xpsFilePaths">A collection of XPS documents.</param>
/// <param name="fastCopy">Whether to validate the XPS documents.</param>
/// <returns>Whether all documents were added to the print queue.</returns>
public static bool BatchAddToPrintQueue(IEnumerable<string> xpsFilePaths, bool fastCopy)
{
    bool allAdded = true;

    // To print without getting the "Save Output File As" dialog, ensure
    // that your default printer is not the Microsoft XPS Document Writer,
    // Microsoft Print to PDF, or other print-to-file option.

    // Get a reference to the default print queue.
    PrintQueue defaultPrintQueue = LocalPrintServer.GetDefaultPrintQueue();

    // Iterate through the document collection.
    foreach (string xpsFilePath in xpsFilePaths)
    {
        // Get document name.
        string xpsFileName = Path.GetFileName(xpsFilePath);

        try
        {
            // The AddJob method adds a new print job for an XPS
            // document into the print queue, and assigns a job name.
            // Use fastCopy to skip XPS validation and progress notifications.
            // If fastCopy is false, the thread that calls PrintQueue.AddJob
            // must have a single-threaded apartment state.
            PrintSystemJobInfo xpsPrintJob =
                    defaultPrintQueue.AddJob(jobName: xpsFileName, documentPath: xpsFilePath, fastCopy);

            // If the queue is not paused and the printer is working, then jobs will automatically begin printing.
            Debug.WriteLine($"Added {xpsFileName} to the print queue.");
        }
        catch (PrintJobException e)
        {
            allAdded = false;
            Debug.WriteLine($"Failed to add {xpsFileName} to the print queue: {e.Message}\r\n{e.InnerException}");
        }
    }

    return allAdded;
}

''' <summary>
''' Asyncronously, add a batch of XPS documents to the print queue using a PrintQueue.AddJob method.
''' Handle the thread apartment state required by the PrintQueue.AddJob method.
''' </summary>
''' <param name="xpsFilePaths">A collection of XPS documents.</param>
''' <param name="fastCopy">Whether to validate the XPS documents.</param>
''' <returns>Whether all documents were added to the print queue.</returns>
Public Shared Async Function BatchAddToPrintQueueAsync(xpsFilePaths As IEnumerable(Of String), Optional fastCopy As Boolean = False) As Task(Of Boolean)

    Dim isAllPrinted As Boolean = True

    ' Queue some work to run on the ThreadPool.
    ' Wait for completion without blocking the calling thread.
    Await Task.Run(
        Sub()
            If fastCopy Then
                isAllPrinted = BatchAddToPrintQueue(xpsFilePaths, fastCopy)
            Else
                ' Create a thread to call the PrintQueue.AddJob method.
                Dim newThread As New Thread(
                    Sub()
                        isAllPrinted = BatchAddToPrintQueue(xpsFilePaths, fastCopy)
                    End Sub
                )

                ' Set the thread to single-threaded apartment state.
                newThread.SetApartmentState(ApartmentState.STA)

                ' Start the thread.
                newThread.Start()

                ' Wait for thread completion. Blocks the calling thread,
                ' which is a ThreadPool thread.
                newThread.Join()
            End If
        End Sub
    )

    Return isAllPrinted

End Function

''' <summary>
''' Add a batch of XPS documents to the print queue using a PrintQueue.AddJob method.
''' </summary>
''' <param name="xpsFilePaths">A collection of XPS documents.</param>
''' <param name="fastCopy">Whether to validate the XPS documents.</param>
''' <returns>Whether all documents were added to the print queue.</returns>
Public Shared Function BatchAddToPrintQueue(xpsFilePaths As IEnumerable(Of String), fastCopy As Boolean) As Boolean

    Dim isAllPrinted As Boolean = True

    ' To print without getting the "Save Output File As" dialog, ensure
    ' that your default printer is not the Microsoft XPS Document Writer,
    ' Microsoft Print to PDF, or other print-to-file option.

    ' Get a reference to the default print queue.
    Dim defaultPrintQueue As PrintQueue = LocalPrintServer.GetDefaultPrintQueue()

    ' Iterate through the document collection.
    For Each xpsFilePath As String In xpsFilePaths

        ' Get document name.
        Dim xpsFileName As String = Path.GetFileName(xpsFilePath)

        Try
            ' The AddJob method adds a new print job for an XPS
            ' document into the print queue, and assigns a job name.
            ' Use fastCopy to skip XPS validation and progress notifications.
            ' If fastCopy is false, the thread that calls PrintQueue.AddJob
            ' must have a single-threaded apartment state.
            Dim xpsPrintJob As PrintSystemJobInfo = defaultPrintQueue.AddJob(jobName:=xpsFileName, documentPath:=xpsFilePath, fastCopy)

            ' If the queue is not paused and the printer is working, then jobs will automatically begin printing.
            Debug.WriteLine($"Added {xpsFileName} to the print queue.")
        Catch e As PrintJobException
            isAllPrinted = False
            Debug.WriteLine($"Failed to add {xpsFileName} to the print queue: {e.Message}\r\n{e.InnerException}")
        End Try
    Next

    Return isAllPrinted

End Function

Consiglio

È anche possibile stampare file XPS usando:

Per altre informazioni, vedere Come visualizzare una finestra di dialogo di stampa e Panoramica della stampa di documenti.

Vedere anche