SAP Crystal Reports for VS2010 databindings, filter not applying

I am using the following code to bind Crystal Reports in page load event.

 using (MilitrymessEntities entity = new MilitrymessEntities())
            {

                BarporderReports barporpt = new BarporderReports();

                barporpt.Refresh();


                barporpt.SetDataSource(query);

                //barporpt.SetParameterValue("norows", 10);
                crviewer_barpurchaseorder.RefreshReport();

                crviewer_barpurchaseorder.ReportSource = barporpt;
            }

It is binding properly and displaying the report. I applied filter to the report in the button click event, when I click the search button, the report is displaying the same set of data. It's not displaying the filtered value. The button click event code follows:

 using (MilitrymessEntities entity = new MilitrymessEntiti开发者_如何学Goes())
        {

            DateTime dt1 = Convert.ToDateTime(txt_fromdate.Text);
            DateTime dt2 = Convert.ToDateTime(txt_todate.Text);

            string strdt1 = dt1.Date.ToString("MM/dd/yyyy");
            string strdt2 = dt2.Date.ToString("MM/dd/yyyy");

            dt1 = Convert.ToDateTime(strdt1);
            dt2 = Convert.ToDateTime(strdt2);


                           var query = from data in entity.BarPurchaseOrders.AsEnumerable()
                         where  (data.Date >= dt1) && (data.Date <= dt2) && data.ItemName == drp_itemname.SelectedItem.Text
                        select data;


                           BarporderReports barporpt = new BarporderReports();
                           barporpt.Refresh();

                           barporpt.SetDataSource(query);


             crviewer_barpurchaseorder.RefreshReport();
            crviewer_barpurchaseorder.ReportSource = barporpt;




        }

Do you have any idea about this problem?

You need to be checking for a post back on page load event. Like below,

if(!page.IsPostback())
{
   using (MilitrymessEntities entity = new MilitrymessEntities())
   {
      BarporderReports barporpt = new BarporderReports();
      barporpt.Refresh();
      barporpt.SetDataSource(query);
      crviewer_barpurchaseorder.RefreshReport();
      crviewer_barpurchaseorder.ReportSource = barporpt;
   }
}

Also, you should be setting your report and data source before refreshing,

BarporderReports barporpt = new BarporderReports();
barporpt.SetDataSource(query);
barporpt.Refresh();

crviewer_barpurchaseorder.ReportSource = barporpt;
crviewer_barpurchaseorder.RefreshReport();