SSRS Report problem in wpf

Question

DataTable reportData = this.GetReportData(startId, endId, empId, minAmount, reportType);


                ReportViewer reportViewer = new ReportViewer();
                reportViewer.ProcessingMode = ProcessingMode.Local;

                reportViewer.LocalReport.ReportEmbeddedResource = "PDCL.ERP.Modules.Marketing.Reports.rptDoctorDetail.rdlc";  

                ReportDataSource ds = new ReportDataSource();
                ds.Name = "DoctorDetail_Report";
                ds.Value = reportData;
                reportViewer.LocalReport.DataSources.Add(ds);


                reportViewer.RefreshReport();
                this.WindowsFrmHost.Child = reportViewer;

this is my code.I'm using SSRS but the viewer only shows but not any data. Why..?