public static byte[] GenerateReport(string dtatSetName, IEnumerable dataSource, string reportFilePath,
                               string reportType, out string mimeType, out string encoding, out string fileNameExtension)
        {
            //报表数据源
            ReportDataSource reportDataSource = new ReportDataSource(dtatSetName, dataSource);
            //本地化报表
            LocalReport localReport = new LocalReport();
            localReport.ReportPath = reportFilePath;
            localReport.DataSources.Add(reportDataSource);

            string deviceInfo =
                "<DeviceInfo>" +
                "  <OutputFormat>" + reportType + "</OutputFormat>" +
                "  <PageWidth>8.5in</PageWidth>" +
                "  <PageHeight>11in</PageHeight>" +
                "  <MarginTop>0.5in</MarginTop>" +
                "  <MarginLeft>1in</MarginLeft>" +
                "  <MarginRight>1in</MarginRight>" +
                "  <MarginBottom>0.5in</MarginBottom>" +
                "</DeviceInfo>";

            Warning[] warnings;
            string[] streams;
            byte[] renderedBytes;

            renderedBytes = localReport.Render(
                reportType,
                deviceInfo,
                out mimeType,
                out encoding,
                out fileNameExtension,
                out streams,
                out warnings);

            return renderedBytes;
        }

 public ActionResult EmployeesNumberPerYear()
        {
            string dtatSetName = "DsENPerYear";
            var dataSource = EmployeeReports.EmployeesNumberPerYear(employeeRepository);
            string reportFilePath = Server.MapPath("~/RDLC/Employee/EmployeesNumberPerYear.rdlc");
            string reportType = "excel";

            string mimeType;
            string encoding;
            string fileNameExtension;

            byte[] renderedBytes = HotelReport.GenerateReport(dtatSetName, dataSource, reportFilePath,
                reportType, out mimeType, out encoding, out fileNameExtension);
            return File(renderedBytes, mimeType);
        }