Hi,
you should handle HiddenChange event of column model. I wrote simple example which using static collection as simple store.
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Collections.Generic"%>
<%@ Register Assembly="Coolite.Ext.Web" Namespace="Coolite.Ext.Web" TagPrefix="ext" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
if (!Ext.IsAjaxRequest)
{
this.Store1.DataSource = new object[]
{
new object[] {"3m Co", 71.72, 0.02, 0.03, "9/1 12:00am"},
new object[] {"Alcoa Inc", 29.01, 0.42, 1.47, "9/1 12:00am"},
new object[] {"Altria Group Inc", 83.81, 0.28, 0.34, "9/1 12:00am"},
new object[] {"American Express Company", 52.55, 0.01, 0.02, "9/1 12:00am"},
new object[] {"American International Group, Inc.", 64.13, 0.31, 0.49, "9/1 12:00am"},
new object[] {"AT&T Inc.", 31.61, -0.48, -1.54, "9/1 12:00am"},
new object[] {"Boeing Co.", 75.43, 0.53, 0.71, "9/1 12:00am"},
new object[] {"Caterpillar Inc.", 67.27, 0.92, 1.39, "9/1 12:00am"},
new object[] {"Citigroup, Inc.", 49.37, 0.02, 0.04, "9/1 12:00am"},
new object[] {"E.I. du Pont de Nemours and Company", 40.48, 0.51, 1.28, "9/1 12:00am"},
new object[] {"Exxon Mobil Corp", 68.1, -0.43, -0.64, "9/1 12:00am"},
new object[] {"General Electric Company", 34.14, -0.08, -0.23, "9/1 12:00am"},
new object[] {"General Motors Corporation", 30.27, 1.09, 3.74, "9/1 12:00am"},
new object[] {"Hewlett-Packard Co.", 36.53, -0.03, -0.08, "9/1 12:00am"},
new object[] {"Honeywell Intl Inc", 38.77, 0.05, 0.13, "9/1 12:00am"},
new object[] {"Intel Corporation", 19.88, 0.31, 1.58, "9/1 12:00am"},
new object[] {"International Business Machines", 81.41, 0.44, 0.54, "9/1 12:00am"},
new object[] {"Johnson & Johnson", 64.72, 0.06, 0.09, "9/1 12:00am"},
new object[] {"JP Morgan & Chase & Co", 45.73, 0.07, 0.15, "9/1 12:00am"},
new object[] {"McDonald\"s Corporation", 36.76, 0.86, 2.40, "9/1 12:00am"},
new object[] {"Merck & Co., Inc.", 40.96, 0.41, 1.01, "9/1 12:00am"},
new object[] {"Microsoft Corporation", 25.84, 0.14, 0.54, "9/1 12:00am"},
new object[] {"Pfizer Inc", 27.96, 0.4, 1.45, "9/1 12:00am"},
new object[] {"The Coca-Cola Company", 45.07, 0.26, 0.58, "9/1 12:00am"},
new object[] {"The Home Depot, Inc.", 34.64, 0.35, 1.02, "9/1 12:00am"},
new object[] {"The Procter & Gamble Company", 61.91, 0.01, 0.02, "9/1 12:00am"},
new object[] {"United Technologies Corporation", 63.26, 0.55, 0.88, "9/1 12:00am"},
new object[] {"Verizon Communications", 35.57, 0.39, 1.11, "9/1 12:00am"},
new object[] {"Wal-Mart Stores, Inc.", 45.45, 0.73, 1.63, "9/1 12:00am"}
};
this.Store1.DataBind();
foreach (KeyValuePair<int, bool> pair in store)
{
GridPanel1.ColumnModel.Columns[pair.Key].Hidden = pair.Value;
}
}
}
private static Dictionary<int, bool> store = new Dictionary<int, bool>();
protected void ColumnHiddenChange(object sender, AjaxEventArgs e)
{
int index = int.Parse(e.ExtraParams["index"]);
bool hidden = bool.Parse(e.ExtraParams["hidden"]);
store[index] = hidden;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Coolite Toolkit Example - Simple Array Grid</title>
</head>
<body>
<form id="form1" runat="server">
<ext:ScriptManager ID="ScriptManager1" runat="server" />
<ext:Store ID="Store1" runat="server">
<Reader>
<ext:ArrayReader>
<Fields>
<ext:RecordField Name="company" />
<ext:RecordField Name="price" Type="Float" />
<ext:RecordField Name="change" Type="Float" />
<ext:RecordField Name="pctChange" Type="Float" />
<ext:RecordField Name="lastChange" Type="Date" DateFormat="n/j h:ia" />
</Fields>
</ext:ArrayReader>
</Reader>
</ext:Store>
<ext:GridPanel
ID="GridPanel1"
runat="server"
StoreID="Store1"
StripeRows="true"
Title="Array Grid"
TrackMouseOver="true"
Width="600"
Height="350"
AutoExpandColumn="Company">
<ColumnModel ID="ColumnModel1" runat="server">
<Columns>
<ext:Column ColumnID="Company" Header="Company" Width="160" Sortable="true" DataIndex="company" />
<ext:Column Header="Price" Width="75" Sortable="true" DataIndex="price"/>
<ext:Column Header="Change" Width="75" Sortable="true" DataIndex="change"/>
<ext:Column Header="Change" Width="75" Sortable="true" DataIndex="pctChange"/>
<ext:Column Header="Last Updated" Width="85" Sortable="true" DataIndex="lastChange">
<Renderer Fn="Ext.util.Format.dateRenderer('m/d/Y')" />
</ext:Column>
</Columns>
<AjaxEvents>
<HiddenChange OnEvent="ColumnHiddenChange">
<ExtraParams>
<ext:Parameter Name="index" Value="columnIndex" Mode="Raw" />
<ext:Parameter Name="hidden" Value="hidden" Mode="Raw" />
</ExtraParams>
</HiddenChange>
</AjaxEvents>
</ColumnModel>
<SelectionModel>
<ext:RowSelectionModel ID="RowSelectionModel1" runat="server" SingleSelect="true" />
</SelectionModel>
</ext:GridPanel>
</form>
</body>
</html>
Hope this help