Comments by Basit Elahi (Top 17 by date)

my project was developed in 4.0 but where i am deploying it, that pc has framework 3.5

i know it is not same and for the same reason i have mentioned at the end that both of these are used to populate drop down list. Now i have improved the question. Please check out the latest one

thanks prasadavunuri. i took idea from this and have solved my problem.

yes it is working fine

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace nested_gridview_from_vb
{
public partial class WebForm1 : System.Web.UI.Page , ITemplate
{
protected void Page_Load(object sender, EventArgs e)
{
hitechLatestEntities database = new hitechLatestEntities();
GridView1.DataSource = database.HEADs;

TemplateField tfObject = new TemplateField();
tfObject.HeaderText = "Sub-Heads Details";

tfObject.ItemTemplate = new WebForm1(ListItemType.Item);
GridView1.Columns.Insert(0,tfObject);
GridView1.DataBind();

}

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{

string headCode = GridView1.DataKeys[e.Row.RowIndex].Value.ToString();

hitechLatestEntities data = new hitechLatestEntities();
var result = from t in data.SUB_HEAD
join x in data.HEADs on t.head_code equals x.head_code
where t.head_code == headCode
select new { t.sub_head_code,t.particulars };

GridView sub = e.Row.FindControl("newg") as GridView;
sub.DataSource = result;
sub.DataBind();

}
}

public WebForm1()
{
}

public WebForm1(ListItemType Item)
{
myListItemType = Item;
}
private ListItemType myListItemType;
public void InstantiateIn(Control container)
{

if (myListItemType == ListItemType.Item)
{
hitechLatestEntities data = new hitechLatestEntities();
GridView newgrid = new GridView();

newgrid.ID = "newg";
newgrid.DataSource = data.SUB_HEAD;
newgrid.DataBind();
container.Controls.Add(newgrid);
}
}
}

for now it has two columns. yes i am doing it from code behind

i have updated the question. please check it

can u give me some example ravikhoda??

<asp:GridView ID="GridView1" runat="server"
onrowdatabound="GridView1_RowDataBound" DataKeyNames="head_code" >


I am doing most of the work programatically

Thanks a lot @JoCodes. Problem solved..!!!

yes data is being fetched by RowDataBound but problem is that same child grid is showing up in each row. i want child gridview according to parent gridview key.

i did like this

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
string headCode = GridView1.DataKeys[e.Row.RowIndex].Value.ToString(); /* it is giving error on this line as "Index was out of range. Must be non-negative and less than the size of the collection" */

hitechLatestEntities data = new hitechLatestEntities();
var result = from t in data.SUB_HEAD
join x in data.HEADs on t.head_code equals x.head_code
where t.head_code == "headCode"
select t;

GridView sub = e.Row.FindControl("newgrid") as GridView;
sub.DataSource = result; /* also on this line as "Object reference not set to an instance of an object." */
sub.DataBind();
}
}

when i put try catch around it, it shows the same result as previous. but child grid is showing up in every row whether it is of that head or not.