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Come visualizzare una finestra di dialogo di stampa (WPF .NET)

  • Articolo

Si vuole stampare dall'applicazione? È possibile utilizzare la PrintDialog classe per aprire una finestra di dialogo di stampa standard di Microsoft Windows. Ecco come.

Nota

Il System.Windows.Controls.PrintDialog controllo usato per WPF e illustrato qui non deve essere confuso con il System.Windows.Forms.PrintDialog componente di Windows Form.

La PrintDialog classe fornisce un singolo controllo per la configurazione di stampa e l'invio di processi di stampa. Il controllo è facile da usare e può essere creata un'istanza usando markup XAML o codice. Gli esempi seguenti creano e visualizzano un'istanza PrintDialog usando il codice .

È possibile utilizzare la finestra di dialogo stampa per configurare le opzioni di stampa, ad esempio:

  • Stampare solo un intervallo specifico di pagine.
  • Selezionare le stampanti installate nel computer. È possibile usare l'opzione Microsoft XPS Document Writer per creare questi tipi di documento:
    • XML Paper Specification (XPS)
    • Open XML Paper Specification (OpenXPS)

In questo esempio vengono stampate tutte le pagine di un documento XPS. Per impostazione predefinita, il codice sarà:

  1. Aprire una finestra di dialogo di stampa che richiede all'utente di selezionare una stampante e avviare un processo di stampa.
  2. Creare un'istanza di un XpsDocument oggetto con il contenuto del documento XPS.
  3. Utilizzare l'oggetto XpsDocument per generare un DocumentPaginator oggetto contenente tutte le pagine del documento XPS.
  4. Chiamare il PrintDocument metodo , passando l'oggetto DocumentPaginator , per inviare tutte le pagine alla stampante specificata.
/// <summary>
/// Print all pages of an XPS document.
/// Optionally, hide the print dialog window.
/// </summary>
/// <param name="xpsFilePath">Path to source XPS file</param>
/// <param name="hidePrintDialog">Whether to hide the print dialog window (shown by default)</param>
/// <returns>Whether the document printed</returns>
public static bool PrintWholeDocument(string xpsFilePath, bool hidePrintDialog = false)
{
    // Create the print dialog object and set options.
    PrintDialog printDialog = new();

    if (!hidePrintDialog)
    {
        // Display the dialog. This returns true if the user presses the Print button.
        bool? isPrinted = printDialog.ShowDialog();
        if (isPrinted != true)
            return false;
    }

    // Print the whole document.
    try
    {
        // Open the selected document.
        XpsDocument xpsDocument = new(xpsFilePath, FileAccess.Read);

        // Get a fixed document sequence for the selected document.
        FixedDocumentSequence fixedDocSeq = xpsDocument.GetFixedDocumentSequence();

        // Create a paginator for all pages in the selected document.
        DocumentPaginator docPaginator = fixedDocSeq.DocumentPaginator;

        // Print to a new file.
        printDialog.PrintDocument(docPaginator, $"Printing {Path.GetFileName(xpsFilePath)}");

        return true;
    }
    catch (Exception e)
    {
        MessageBox.Show(e.Message);

        return false;
    }
}

''' <summary>
''' Print all pages of an XPS document.
''' Optionally, print all pages without showing a print dialog window.
''' </summary>
''' <param name="xpsFilePath">Path to source XPS file</param>
''' <param name="hidePrintDialog">Whether to hide the print dialog window (shown by default)</param>
''' <returns>Whether the document printed</returns>
Public Shared Function PrintWholeDocument(xpsFilePath As String, Optional hidePrintDialog As Boolean = False) As Boolean

    ' Create the print dialog object and set options.
    Dim printDialog As New PrintDialog

    If Not hidePrintDialog Then

        ' Display the dialog. This returns true if the user presses the Print button.
        Dim isPrinted As Boolean? = printDialog.ShowDialog()
        If isPrinted <> True Then Return False

    End If

    ' Print the whole document.
    Try

        ' Open the selected document.
        Dim xpsDocument As New XpsDocument(xpsFilePath, FileAccess.Read)

        ' Get a fixed document sequence for the selected document.
        Dim fixedDocSeq As FixedDocumentSequence = xpsDocument.GetFixedDocumentSequence()

        ' Create a paginator for all pages in the selected document.
        Dim docPaginator As DocumentPaginator = fixedDocSeq.DocumentPaginator

        ' Print to a new file.
        printDialog.PrintDocument(docPaginator, $"Printing {Path.GetFileName(xpsFilePath)}")

        Return True

    Catch e As Exception

        MessageBox.Show(e.Message)

        Return False

    End Try

End Function

Stampare un intervallo di pagine

A volte si desidera stampare solo un intervallo specifico di pagine all'interno di un documento XPS. A tale scopo, si estende la classe astratta DocumentPaginator per aggiungere il supporto per gli intervalli di pagine. Per impostazione predefinita, il codice sarà:

  1. Aprire una finestra di dialogo di stampa che richiede all'utente di selezionare una stampante, specificare un intervallo di pagine e avviare un processo di stampa.
  2. Creare un'istanza di un XpsDocument oggetto con il contenuto del documento XPS.
  3. Utilizzare l'oggetto XpsDocument per generare un oggetto predefinito DocumentPaginator che contiene tutte le pagine del documento XPS.
  4. Creare un'istanza di una classe estesa DocumentPaginator che supporta gli intervalli di pagine, passando l'oggetto predefinito DocumentPaginator e lo PageRange struct restituito da PrintDialog.
  5. Chiamare il PrintDocument metodo , passando l'istanza della classe estesa DocumentPaginator , per inviare l'intervallo di pagine specificato alla stampante specificata.
/// <summary>
/// Print a specific range of pages within an XPS document.
/// </summary>
/// <param name="xpsFilePath">Path to source XPS file</param>
/// <returns>Whether the document printed</returns>
public static bool PrintDocumentPageRange(string xpsFilePath)
{
    // Create the print dialog object and set options.
    PrintDialog printDialog = new()
    {
        UserPageRangeEnabled = true
    };

    // Display the dialog. This returns true if the user presses the Print button.
    bool? isPrinted = printDialog.ShowDialog();
    if (isPrinted != true)
        return false;

    // Print a specific page range within the document.
    try
    {
        // Open the selected document.
        XpsDocument xpsDocument = new(xpsFilePath, FileAccess.Read);

        // Get a fixed document sequence for the selected document.
        FixedDocumentSequence fixedDocSeq = xpsDocument.GetFixedDocumentSequence();

        // Create a paginator for all pages in the selected document.
        DocumentPaginator docPaginator = fixedDocSeq.DocumentPaginator;

        // Check whether a page range was specified in the print dialog.
        if (printDialog.PageRangeSelection == PageRangeSelection.UserPages)
        {
            // Create a document paginator for the specified range of pages.
            docPaginator = new DocPaginator(fixedDocSeq.DocumentPaginator, printDialog.PageRange);
        }

        // Print to a new file.
        printDialog.PrintDocument(docPaginator, $"Printing {Path.GetFileName(xpsFilePath)}");

        return true;
    }
    catch (Exception e)
    {
        MessageBox.Show(e.Message);

        return false;
    }
}

/// <summary>
/// Extend the abstract DocumentPaginator class to support page range printing. This class is based on the following online resources:
///
/// https://www.thomasclaudiushuber.com/2009/11/24/wpf-printing-how-to-print-a-pagerange-with-wpfs-printdialog-that-means-the-user-can-select-specific-pages-and-only-these-pages-are-printed/
///
/// https://social.msdn.microsoft.com/Forums/vstudio/en-US/9180e260-0791-4f2d-962d-abcb22ba8d09/how-to-print-multiple-page-ranges-with-wpf-printdialog
///
/// https://social.msdn.microsoft.com/Forums/en-US/841e804b-9130-4476-8709-0d2854c11582/exception-quotfixedpage-cannot-contain-another-fixedpagequot-when-printing-to-the-xps-document?forum=wpf
/// </summary>
public class DocPaginator : DocumentPaginator
{
    private readonly DocumentPaginator _documentPaginator;
    private readonly int _startPageIndex;
    private readonly int _endPageIndex;
    private readonly int _pageCount;

    public DocPaginator(DocumentPaginator documentPaginator, PageRange pageRange)
    {
        // Set document paginator.
        _documentPaginator = documentPaginator;

        // Set page indices.
        _startPageIndex = pageRange.PageFrom - 1;
        _endPageIndex = pageRange.PageTo - 1;

        // Validate and set page count.
        if (_startPageIndex >= 0 &&
            _endPageIndex >= 0 &&
            _startPageIndex <= _documentPaginator.PageCount - 1 &&
            _endPageIndex <= _documentPaginator.PageCount - 1 &&
            _startPageIndex <= _endPageIndex)
            _pageCount = _endPageIndex - _startPageIndex + 1;
    }

    public override bool IsPageCountValid => true;

    public override int PageCount => _pageCount;

    public override IDocumentPaginatorSource Source => _documentPaginator.Source;

    public override Size PageSize { get => _documentPaginator.PageSize; set => _documentPaginator.PageSize = value; }

    public override DocumentPage GetPage(int pageNumber)
    {
        DocumentPage documentPage = _documentPaginator.GetPage(_startPageIndex + pageNumber);

        // Workaround for "FixedPageInPage" exception.
        if (documentPage.Visual is FixedPage fixedPage)
        {
            var containerVisual = new ContainerVisual();
            foreach (object child in fixedPage.Children)
            {
                var childClone = (UIElement)child.GetType().GetMethod("MemberwiseClone", BindingFlags.Instance | BindingFlags.NonPublic).Invoke(child, null);

                FieldInfo parentField = childClone.GetType().GetField("_parent", BindingFlags.Instance | BindingFlags.NonPublic);
                if (parentField != null)
                {
                    parentField.SetValue(childClone, null);
                    containerVisual.Children.Add(childClone);
                }
            }

            return new DocumentPage(containerVisual, documentPage.Size, documentPage.BleedBox, documentPage.ContentBox);
        }

        return documentPage;
    }
}

''' <summary>
''' Print a specific range of pages within an XPS document.
''' </summary>
''' <param name="xpsFilePath">Path to source XPS file</param>
''' <returns>Whether the document printed</returns>
Public Shared Function PrintDocumentPageRange(xpsFilePath As String) As Boolean

    ' Create the print dialog object and set options.
    Dim printDialog As New PrintDialog With {
        .UserPageRangeEnabled = True
    }

    ' Display the dialog. This returns true if the user presses the Print button.
    Dim isPrinted As Boolean? = printDialog.ShowDialog()
    If isPrinted <> True Then Return False

    ' Print a specific page range within the document.
    Try

        ' Open the selected document.
        Dim xpsDocument As New XpsDocument(xpsFilePath, FileAccess.Read)

        ' Get a fixed document sequence for the selected document.
        Dim fixedDocSeq As FixedDocumentSequence = xpsDocument.GetFixedDocumentSequence()

        ' Create a paginator for all pages in the selected document.
        Dim docPaginator As DocumentPaginator = fixedDocSeq.DocumentPaginator

        ' Check whether a page range was specified in the print dialog.
        If printDialog.PageRangeSelection = PageRangeSelection.UserPages Then

            ' Create a document paginator for the specified range of pages.
            docPaginator = New DocPaginator(fixedDocSeq.DocumentPaginator, printDialog.PageRange)

        End If

        ' Print to a new file.
        printDialog.PrintDocument(docPaginator, $"Printing {Path.GetFileName(xpsFilePath)}")

        Return True

    Catch e As Exception

        MessageBox.Show(e.Message)

        Return False

    End Try

End Function

' Extend the abstract DocumentPaginator class to support page range printing.
' This class is based on the following online resources:
' https://www.thomasclaudiushuber.com/2009/11/24/wpf-printing-how-to-print-a-pagerange-with-wpfs-printdialog-
' that-means-the-user-can-select-specific-pages-and-only-these-pages-are-printed/
' https://social.msdn.microsoft.com/Forums/vstudio/en-US/9180e260-0791-4f2d-962d-abcb22ba8d09/how-to-print-
' multiple-page-ranges-with-wpf-printdialog
' https://social.msdn.microsoft.com/Forums/en-US/841e804b-9130-4476-8709-0d2854c11582/exception-quotfixedpage-
' cannot-contain-another-fixedpagequot-when-printing-to-the-xps-document?forum=wpf
Public Class DocPaginator
    Inherits DocumentPaginator

    Private ReadOnly _documentPaginator As DocumentPaginator
    Private ReadOnly _startPageIndex As Integer
    Private ReadOnly _endPageIndex As Integer
    Private ReadOnly _pageCount As Integer

    Public Sub New(documentPaginator As DocumentPaginator, pageRange As PageRange)

        ' Set document paginator.
        _documentPaginator = documentPaginator

        ' Set page indices.
        _startPageIndex = pageRange.PageFrom - 1
        _endPageIndex = pageRange.PageTo - 1

        ' Validate And set page count.
        If _startPageIndex >= 0 AndAlso
            _endPageIndex >= 0 AndAlso
            _startPageIndex <= _documentPaginator.PageCount - 1 AndAlso
            _endPageIndex <= _documentPaginator.PageCount - 1 AndAlso
            _startPageIndex <= _endPageIndex Then
            _pageCount = _endPageIndex - _startPageIndex + 1
        End If

    End Sub

    Public Overrides ReadOnly Property IsPageCountValid As Boolean
        Get
            Return True
        End Get
    End Property

    Public Overrides ReadOnly Property PageCount As Integer
        Get
            Return _pageCount
        End Get
    End Property

    Public Overrides ReadOnly Property Source As IDocumentPaginatorSource
        Get
            Return _documentPaginator.Source
        End Get
    End Property

    Public Overrides Property PageSize As Size
        Get
            Return _documentPaginator.PageSize
        End Get
        Set(value As Size)
            _documentPaginator.PageSize = value
        End Set
    End Property

    Public Overrides Function GetPage(pageNumber As Integer) As DocumentPage

        Dim documentPage As DocumentPage = _documentPaginator.GetPage(_startPageIndex + pageNumber)

        ' Workaround for "FixedPageInPage" exception.
        If documentPage.Visual.GetType() Is GetType(FixedPage) Then

            Dim fixedPage As FixedPage = documentPage.Visual
            Dim containerVisual = New ContainerVisual()

            For Each child As Object In fixedPage.Children
                Dim childClone = CType(child.[GetType]().GetMethod("MemberwiseClone", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(child, Nothing), UIElement)
                Dim parentField As FieldInfo = childClone.[GetType]().GetField("_parent", BindingFlags.Instance Or BindingFlags.NonPublic)

                If parentField IsNot Nothing Then
                    parentField.SetValue(childClone, Nothing)
                    containerVisual.Children.Add(childClone)
                End If
            Next

            Return New DocumentPage(containerVisual, documentPage.Size, documentPage.BleedBox, documentPage.ContentBox)

        End If

        Return documentPage

    End Function

End Class

Suggerimento

Sebbene sia possibile utilizzare il PrintDocument metodo per stampare senza aprire la finestra di dialogo di stampa, per motivi di prestazioni è preferibile usare il AddJob metodo o uno dei molti Write metodi e WriteAsync di XpsDocumentWriter. Per altre informazioni, vedere Come stampare un file XPS e la panoramica dei documenti di stampa.

Vedi anche