ReportView1.Reset();
Dataset ds=new DataSet();
            ReportView1.ProcessingMode = ProcessingMode.Local;
            Microsoft.Reporting.WebForms.ReportDataSource rds = new ReportDataSource();
            rds.Value = ds.Tables[0];
            LocalReport r = ReportView1.LocalReport;
            r.DataSources.Add(rds);//add datasource

------解决方案--------------------

C# code

            ReportDataSource myRptDS = new ReportDataSource();
            myRptDS.DataSourceId = "ObjectDataSource1";
            ReportViewer1.LocalReport.DataSources.Add(myRptDS);
            ReportViewer1.LocalReport.Refresh();