RDLC报表后台输出PDF文件

private List<Stream> _pdfStreamList;
		//先生成PDF数据
        public  void ExportPDF(LocalReport pReport) {
            //pReport.Render(
            Warning[] pWarnings;            //存储警告项
            string[] pStreamids;
            string pMimeType;
            string pEncoding;
            string pExtensions;
            byte[] pBytes = pReport.Render("PDF", null, out pMimeType, out pEncoding,out  pExtensions,out pStreamids,out pWarnings);
            if (_pdfStreamList == null) {
                _pdfStreamList = new List<Stream>();
            }
            MemoryStream  pStream = new MemoryStream();
            //if (_pdfStream == null) {
            //    _pdfStream = new MemoryStream();
            //}
            //else {
               
            //}
            pStream.Write(pBytes, 0, pBytes.Length);
            _pdfStreamList.Add(pStream);
         }

      	//把PDF数据写入文件
		public void savePDFFile(string pFileName) {
            if (_pdfStreamList == null) {
                throw new RDLFProxyException("在未调用ExportPDF生成报表数据之前，不能调用savePDFFile生成pdf文件");
            }
            FileStream pFileStream = new FileStream(pFileName, FileMode.Create);
            foreach (MemoryStream pStream in _pdfStreamList) {
                byte[] pBuffer = new byte[(int)pStream.Length];
                pStream.Seek(0, SeekOrigin.Begin);
                pStream.Read(pBuffer, 0, (int)pStream.Length);
                pFileStream.Write(pBuffer, 0, pBuffer.Length);
                break;
            }
            pFileStream.Close();
           
        }