RadCombobox SelectedIndexChanged property

[Anagha]

Hello Telerik Team

I'm using RadControl version : 2011.1.315.35 (for ASP.NET AJAX). I am using the Radgrid control also.
I have a simple problem. I just want to load record in Radgrid control on selection of a value in Radcombobox.
Here is the code,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using Telerik.Web.UI;

public partial class GridDemo2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

        using (SqlConnection con1 = new SqlConnection(ConfigurationManager.ConnectionStrings["connect"].ConnectionString))
        {
            using (SqlDataAdapter sda1 = new SqlDataAdapter())
            {
                string qry = "select * from Categories";
                sda1.SelectCommand = new SqlCommand(qry, con1);
                DataTable dt = new DataTable();

                con1.Open();
                try
                {
                    sda1.Fill(dt);
                    RadGrid1.DataSource = dt;
                }
                catch (Exception ex) {
                }
                finally
                {
                    con1.Close();
                }
            }
        }
    }
    protected void RadComboBox1_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
    {
        if (IsPostBack)
        {
            using (SqlConnection con1 = new SqlConnection(ConfigurationManager.ConnectionStrings["connect"].ConnectionString))
            {                
              using (SqlDataAdapter sda1 = new SqlDataAdapter())
            {
              string qry = "select * from Categories where Category_Name = '" + RadComboBox1.SelectedValue.ToString() + "'";
                sda1.SelectCommand = new SqlCommand(qry, con1);
                DataTable dt = new DataTable();

                con1.Open();
                try
                {
                    sda1.Fill(dt);
                    RadGrid1.DataSource = dt;
                }
                catch (Exception ex) {
                }
                finally
                {
                    con1.Close();
                }
            }
        }
    }
}

In this example I have taken a radcombobox which is bind to Categories table and datafield value is category name.
I want to fill the rad grid when radcombobox value is selected. I am passing that value in the query and on that query i want to load that 
record in the radgrid. I am not able to bind the data to radgrid.

If I am wrong in coding then please help me out.

Thanks in advance.

Regards
Anagha

[Dimitar Terziev]

Hello Anagha,

The reason for the experienced behavior is the fact that you should call the DataBind() method of the RadGird.Currently you are just assigning a data source to the RadGrid, but then nothing is causing the grid to bind to this data source.

Change your event handling function to the following:

protected void RadComboBox1_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
   {
       if (IsPostBack)
       {
           using (SqlConnection con1 = new SqlConnection(ConfigurationManager.ConnectionStrings["connect"].ConnectionString))
           {
             using (SqlDataAdapter sda1 = new SqlDataAdapter())
           {
             string qry = "select * from Categories where Category_Name = '" + RadComboBox1.SelectedValue.ToString() + "'";
               sda1.SelectCommand = new SqlCommand(qry, con1);
               DataTable dt = new DataTable();

               con1.Open();
               try
               {
                   sda1.Fill(dt);
                   RadGrid1.DataSource = dt;
                   RadGrid1.DataBind();
               }
               catch (Exception ex) {
               }
               finally
               {
                   con1.Close();
               }
           }
       }
   }

I hope this would help you out.

Best wishes,
Dimitar Terziev
the Telerik team