wpf - 打印 WPF FlowDocument

Question

我正在用 WPF 构建一个演示应用程序，这对我来说是新的。我目前在 FlowDocument 中显示文本，需要打印它。

我正在使用的代码如下所示:

        PrintDialog pd = new PrintDialog();
        fd.PageHeight = pd.PrintableAreaHeight;
        fd.PageWidth = pd.PrintableAreaWidth;
        fd.PagePadding = new Thickness(50);
        fd.ColumnGap = 0;
        fd.ColumnWidth = pd.PrintableAreaWidth;

        IDocumentPaginatorSource dps = fd;
        pd.PrintDocument(dps.DocumentPaginator, "flow doc");

fd 是我的 FlowDocument，现在我使用默认打印机而不是允许用户指定打印选项。它工作正常，除了文档打印后，屏幕上显示的 FlowDocument 已更改为使用我指定的打印设置。

我可以通过在打印后手动重置所有内容来解决此问题，但这是最好的方法吗？在打印 FlowDocument 之前，我应该制作它的副本吗？或者我应该考虑另一种方法吗？

Answer 1

是的，在打印之前制作 FlowDocument 的副本。这是因为分页和边距会不同。这对我有用。

    private void DoThePrint(System.Windows.Documents.FlowDocument document)
    {
        // Clone the source document's content into a new FlowDocument.
        // This is because the pagination for the printer needs to be
        // done differently than the pagination for the displayed page.
        // We print the copy, rather that the original FlowDocument.
        System.IO.MemoryStream s = new System.IO.MemoryStream();
        TextRange source = new TextRange(document.ContentStart, document.ContentEnd);
        source.Save(s, DataFormats.Xaml);
        FlowDocument copy = new FlowDocument();
        TextRange dest = new TextRange(copy.ContentStart, copy.ContentEnd);
        dest.Load(s, DataFormats.Xaml);

        // Create a XpsDocumentWriter object, implicitly opening a Windows common print dialog,
        // and allowing the user to select a printer.

        // get information about the dimensions of the seleted printer+media.
        System.Printing.PrintDocumentImageableArea ia = null;
        System.Windows.Xps.XpsDocumentWriter docWriter = System.Printing.PrintQueue.CreateXpsDocumentWriter(ref ia);

        if (docWriter != null && ia != null)
        {
            DocumentPaginator paginator = ((IDocumentPaginatorSource)copy).DocumentPaginator;

            // Change the PageSize and PagePadding for the document to match the CanvasSize for the printer device.
            paginator.PageSize = new Size(ia.MediaSizeWidth, ia.MediaSizeHeight);
            Thickness t = new Thickness(72);  // copy.PagePadding;
            copy.PagePadding = new Thickness(
                             Math.Max(ia.OriginWidth, t.Left),
                               Math.Max(ia.OriginHeight, t.Top),
                               Math.Max(ia.MediaSizeWidth - (ia.OriginWidth + ia.ExtentWidth), t.Right),
                               Math.Max(ia.MediaSizeHeight - (ia.OriginHeight + ia.ExtentHeight), t.Bottom));

            copy.ColumnWidth = double.PositiveInfinity;
            //copy.PageWidth = 528; // allow the page to be the natural with of the output device

            // Send content to the printer.
            docWriter.Write(paginator);
        }

    }