ReportViewer 不预览，直接导出 PDF文件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.IO;
using System.Data;
using Microsoft.Reporting.WinForms;
using System.Drawing.Printing;
using System.Drawing.Imaging;
using System.Drawing;
namespace PrintLocalReport
{
    public enum ExportFileType
    {
        PDF
    }
   public class ReportViewerPrinter:IDisposable
   {
       private int m_currentPageIndex = 0;
       private IList<Stream> m_streams;


　　   private Stream CreateStream(string name, string fileNameExtension, Encoding encoding,
           string mimeType, bool willSeek)
       {
           Stream stream = new MemoryStream();
           m_streams.Add(stream);
           return stream;
       }

       public void ExportToFile(LocalReport report,string targetPath, ExportFileType fileType)
       {
           Export(report, targetPath, fileType);
       }

       private void Export(LocalReport report, string targetPath, ExportFileType fileType)
       {
           string deviceInfo =
           @"<DeviceInfo>
                <OutputFormat>EMF</OutputFormat>
            </DeviceInfo>";
　　　　　　　//根据我的测试，这里的参数会覆盖rdlc中定义的参数，所以我尝试删除了，发现删除了行为是可预期的，是正确的
　　　　　　　//如果需要，这里可以实现定制化了

           //<PageWidth>8.5in</PageWidth>
           //<PageHeight>11in</PageHeight>
           //<MarginTop>0.25in</MarginTop>
           //<MarginLeft>0.25in</MarginLeft>
           //<MarginRight>0.25in</MarginRight>
           //<MarginBottom>0.25in</MarginBottom>

           Warning[] warnings;
           m_streams = new List<Stream>();
           report.Render(fileType.ToString(), deviceInfo, CreateStream,
              out warnings);
           int bufferLength = 1024;
           byte[] buffer = new byte[bufferLength];
           using (FileStream fs = new FileStream(targetPath, FileMode.CreateNew, FileAccess.Write))
           {
               foreach (Stream stream in m_streams)
               {
                   stream.Position = 0;
                   MemoryStream ms = stream as MemoryStream;
                   int readLength = 0;
                   while (true)
                   {
                       readLength = ms.Read(buffer, 0, bufferLength);
                       if (readLength == 0) break;
                       fs.Write(buffer, 0, readLength);
                   }
               }
           }
       }

       private void PrintPage(object sender, PrintPageEventArgs ev)
       {
           Metafile pageImage = new Metafile(m_streams[m_currentPageIndex]);
           Rectangle adjustedRect = new Rectangle(

               ev.PageBounds.Left - (int)ev.PageSettings.HardMarginX,
               ev.PageBounds.Top - (int)ev.PageSettings.HardMarginY,
               ev.PageBounds.Width,
               ev.PageBounds.Height);

           ev.Graphics.FillRectangle(Brushes.Wheat, adjustedRect);
           ev.Graphics.DrawImage(pageImage, adjustedRect);
           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();
           }
       }

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