protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        Random rnd = new Random();
        DataSet1.DataTable1DataTable table = new DataSet1.DataTable1DataTable();
        for (int i = 0; i < 24; i++)
        {
            table.Rows.Add(rnd.Next(1000), i);
        }

        //报表文件
        ReportViewer1.LocalReport.ReportPath = Server.MapPath("Report.rdlc");

        //报表参数：
        //一定要放在ReportPath之后赋值，否则出错：尚未指定报表定义的来源
        ReportParameter[] parameters = new ReportParameter[1];
        parameters[0] = new ReportParameter("Param1", "绘制时间：" + DateTime.Now.ToString());
        ReportViewer1.LocalReport.SetParameters(parameters);

        //报表数据源
        ReportDataSource rds = new ReportDataSource("DataSet1_DataTable1", table);
        ReportViewer1.LocalReport.DataSources.Clear();
        ReportViewer1.LocalReport.DataSources.Add(rds);
        
        //报表刷新并显示
        ReportViewer1.LocalReport.Refresh();
    }
}