【翻译】打印RichTextBox内容：（寻找空闲打印机）

http://blogs.msdn.com/b/llobo/archive/2007/01/24/printing-richtextbox-content-find-the-idle-printer.aspx

最近, Praj发表了关于打印RichTextBox内容的博文。一般，如果你使用documentPaginator或者visual，你可能因一些文本剪贴而终止。这可不是好事。当打印时容易出的bug是打印对话框。通常，我想使用空闲的打印机，而不是让我等待。下面是我针对此修改的代码。

 

foreach (PrintQueue pq in GetPrintQueues("\\\\servername"))

            {

                if (!pq.IsBusy)

                {

                   Print(pq);

                   return;

                }

            }

        private IEnumerable<PrintQueue> GetPrintQueues(string servername)

        {

            PrintServer ps;

 

            if (string.IsNullOrEmpty(servername))

            {

                // local printer name

                ps = new LocalPrintServer();

            }

            else

            {

                // network printer share

                ps = new PrintServer(servername);

            }

 

            return ps.GetPrintQueues();

       }

        void Print(PrintQueue pq)

        {

            TextRange sourceDocument = new TextRange(richTextBox.Document.ContentStart, richTextBox.Document.ContentEnd);

            MemoryStream stream = new MemoryStream();

            sourceDocument.Save(stream, DataFormats.Xaml);

 

           // Clone the source document's content into a new FlowDocument.

            FlowDocument flowDocumentCopy = new FlowDocument();

            TextRange copyDocumentRange = new TextRange(flowDocumentCopy.ContentStart, flowDocumentCopy.ContentEnd);

            copyDocumentRange.Load(stream, DataFormats.Xaml);

 

            // Create a XpsDocumentWriter object, open a Windows common print dialog.

            // This methods returns a ref parameter that represents information about the dimensions of the printer media.

            XpsDocumentWriter docWriter = PrintQueue.CreateXpsDocumentWriter(pq);

            PageImageableArea ia = pq.GetPrintCapabilities().PageImageableArea;

            PrintTicket pt = pq.UserPrintTicket;

 

            if (docWriter != null && ia != null)

            {

                DocumentPaginator paginator = ((IDocumentPaginatorSource)flowDocumentCopy).DocumentPaginator;

                // Change the PageSize and PagePadding for the document to match the CanvasSize for the printer device.

                paginator.PageSize = new Size((double)pt.PageMediaSize.Width, (double)pt.PageMediaSize.Height);

                Thickness pagePadding = flowDocumentCopy.PagePadding;

                flowDocumentCopy.PagePadding = new Thickness(

                        Math.Max(ia.OriginWidth, pagePadding.Left),

                        Math.Max(ia.OriginHeight, pagePadding.Top),

                        Math.Max((double)pt.PageMediaSize.Width - (double)(ia.OriginWidth + ia.ExtentWidth), pagePadding.Right),

                        Math.Max((double)pt.PageMediaSize.Height - (double)(ia.OriginHeight + ia.ExtentHeight), pagePadding.Bottom));

                flowDocumentCopy.ColumnWidth = double.PositiveInfinity;

                // Send DocumentPaginator to the printer.

                docWriter.Write(paginator);

            }

        }