如何在没有对话的情况下直接将报告打印到打印机

Question

我在下面看到了Microsoft课程，但我无法理解任何人都可以帮助我。我的报告打印产品，并在Sql server数据库中使用存储过程调用这些产品。

    public class Demo : IDisposable
    { 
        private int m_currentPageIndex;

        private IList m_streams;

        private DataTable LoadSalesData()
        {
            // Create a new DataSet and read sales data file 
            //    data.xml into the first DataTable.
            DataSet dataSet = new DataSet();
            dataSet.ReadXml(@"..\..\data.xml");
            return dataSet.Tables[0];
        }
        // Routine to provide to the report renderer, in order to
        //    save an image for each page of the report.
        private Stream CreateStream(string name,
          string fileNameExtension, Encoding encoding,
          string mimeType, bool willSeek)
        {
            Stream stream = new MemoryStream();
            m_streams.Add(stream);
            return stream;
        }
        // Export the given report as an EMF (Enhanced Metafile) file.
        private void Export(LocalReport report)
        {
            string deviceInfo =
              @"<DeviceInfo>
                    <OutputFormat>EMF</OutputFormat>
                    <PageWidth>8.5in</PageWidth>
                    <PageHeight>11in</PageHeight>
                    <MarginTop>0.25in</MarginTop>
                    <MarginLeft>0.25in</MarginLeft>
                    <MarginRight>0.25in</MarginRight>
                    <MarginBottom>0.25in</MarginBottom>
                </DeviceInfo>";
            Warning[] warnings;
            m_streams = new List<Stream>();
            report.Render("Image", deviceInfo, CreateStream,
               out warnings);
            foreach (Stream stream in m_streams)
                stream.Position = 0;
        }
        // Handler for PrintPageEvents
        private void PrintPage(object sender, PrintPageEventArgs ev)
        {
            Metafile pageImage = new
               Metafile(m_streams[m_currentPageIndex]);

            // Adjust rectangular area with printer margins.
            Rectangle adjustedRect = new Rectangle(
                ev.PageBounds.Left - (int)ev.PageSettings.HardMarginX,
                ev.PageBounds.Top - (int)ev.PageSettings.HardMarginY,
                ev.PageBounds.Width,
                ev.PageBounds.Height);

            // Draw a white background for the report
            ev.Graphics.FillRectangle(Brushes.White, adjustedRect);

            // Draw the report content
            ev.Graphics.DrawImage(pageImage, adjustedRect);

            // Prepare for the next page. Make sure we haven't hit the end.
            m_currentPageIndex++;
            ev.HasMorePages = (m_currentPageIndex < m_streams.Count);
        }

        private void Print()
        {
            if (m_streams == null || m_streams.Count == 0)
                throw new Exception("Error: no stream to print.");
            PrintDocument printDoc = new PrintDocument();
            if (!printDoc.PrinterSettings.IsValid)
            {
                throw new Exception("Error: cannot find the default printer.");
            }
            else
            {
                printDoc.PrintPage += new PrintPageEventHandler(PrintPage);
                m_currentPageIndex = 0;
                printDoc.Print();
            }
        }
        // Create a local report for Report.rdlc, load the data,
        //    export the report to an .emf file, and print it.
        private void Run()
        {
            LocalReport report = new LocalReport();
            report.ReportPath = @"..\..\Report.rdlc";
            report.DataSources.Add(
               new ReportDataSource("Sales", LoadSalesData()));
            Export(report);
            Print();
        }

        public void Dispose()
        {
            if (m_streams != null)
            {
                foreach (Stream stream in m_streams)
                    stream.Close();
                m_streams = null;
            }
        }

        public static void Main(string[] args)
        {
            using (Demo demo = new Demo())
            {
                demo.Run();
            }
        }
    }