I had to prepare a sample which lead to delay. Try this
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<style type="text/css">
body
{
font-family: Arial;
font-size: 10pt;
}
.Grid td
{
background-color: #A1DCF2;
color: black;
font-size: 10pt;
line-height: 200%;
}
.Grid th
{
background-color: #3AC0F2;
color: White;
font-size: 10pt;
line-height: 200%;
}
.ChildGrid td
{
background-color: #eee !important;
color: black;
font-size: 10pt;
line-height: 200%;
}
.ChildGrid th
{
background-color: #6C6C6C !important;
color: White;
font-size: 10pt;
line-height: 200%;
}
</style>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script type="text/javascript">
$("[src*=plus]").live("click", function () {
$(this).closest("tr").after("<tr><td></td><td colspan = '999'>" + $(this).next().html() + "</td></tr>")
$(this).attr("src", "images/minus.png");
$(this).next().next().val(1);
});
$("[src*=minus]").live("click", function () {
$(this).attr("src", "images/plus.png");
$(this).closest("tr").next().remove();
$(this).next().next().val("");
});
$(function () {
$("[id*=IsExpanded]").each(function () {
if ($(this).val() == "1") {
$(this).closest("tr").after("<tr><td></td><td colspan = '999'>" + $("[id*=pnlOrders]", $(this).closest("tr")).html() + "</td></tr>")
$("[src*=plus]", $(this).closest("tr")).attr("src", "images/minus.png");
}
});
})
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" />
<asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false" CssClass="Grid"
DataKeyNames="CustomerID" OnRowDataBound="OnRowDataBound">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<img alt="" style="cursor: pointer" src="images/plus.png" />
<asp:Panel ID="pnlOrders" runat="server" Style="display: none">
<asp:GridView ID="gvOrders" runat="server" AutoGenerateColumns="false" CssClass="ChildGrid">
<Columns>
<asp:BoundField ItemStyle-Width="150px" DataField="OrderId" HeaderText="Order Id" />
<asp:BoundField ItemStyle-Width="150px" DataField="OrderDate" HeaderText="Date" />
</Columns>
</asp:GridView>
</asp:Panel>
<asp:HiddenField ID="IsExpanded" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField ItemStyle-Width="150px" DataField="ContactName" HeaderText="Contact Name" />
<asp:BoundField ItemStyle-Width="150px" DataField="City" HeaderText="City" />
</Columns>
</asp:GridView>
</form>
</body>
</html>
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
gvCustomers.DataSource = GetData("select top 10 * from Customers");
gvCustomers.DataBind();
}
//For Re Exapnding the expanded rows
foreach (GridViewRow row in gvCustomers.Rows)
{
if (row.RowType == DataControlRowType.DataRow)
{
HiddenField IsExpanded = row.FindControl("IsExpanded") as HiddenField;
IsExpanded.Value = Request.Form[IsExpanded.UniqueID];
}
}
}
private static DataTable GetData(string query)
{
string strConnString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(strConnString))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = query;
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataSet ds = new DataSet())
{
DataTable dt = new DataTable();
sda.Fill(dt);
return dt;
}
}
}
}
}
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
string customerId = gvCustomers.DataKeys[e.Row.RowIndex].Value.ToString();
GridView gvOrders = e.Row.FindControl("gvOrders") as GridView;
gvOrders.DataSource = GetData(string.Format("select top 3 * from Orders where CustomerId='{0}'", customerId));
gvOrders.DataBind();
}
}
