Hello everyone!
I have a grid panel and store bounded to data table.
After "Post Back" button causes a post back and page re loads , the data on gridpanel is lost.
But when you click on "To XML" button, the data on gridpanel is still retain.
Please tell me how to persist the state of grid after post back without setting the data source everytime.

This is my sample:


<%@ Page Language="C#" %>

<%@ Import Namespace="System.Xml.Xsl" %>
<%@ Import Namespace="System.Xml" %>

<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>

<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            this.Store1.DataSource = new object[]
            {
                new object[] { 1, "3m Co", 71.72, 0.02, 0.03, "9/1 12:00am" },
                new object[] { 2, "Alcoa Inc", 29.01, 0.42, 1.47, "9/1 12:00am" },
                new object[] { 3, "Altria Group Inc", 83.81, 0.28, 0.34, "9/1 12:00am" },
                new object[] { 4, "American Express Company", 52.55, 0.01, 0.02, "9/1 12:00am" },
                new object[] { 5, "American International Group, Inc.", 64.13, 0.31, 0.49, "9/1 12:00am" },
                new object[] { 6, "AT&T Inc.", 31.61, -0.48, -1.54, "9/1 12:00am" },
                new object[] { 7, "Boeing Co.", 75.43, 0.53, 0.71, "9/1 12:00am" },
                new object[] { 8, "Caterpillar Inc.", 67.27, 0.92, 1.39, "9/1 12:00am" },
                new object[] { 9, "Citigroup, Inc.", 49.37, 0.02, 0.04, "9/1 12:00am" },
                new object[] { 10, "E.I. du Pont de Nemours and Company", 40.48, 0.51, 1.28, "9/1 12:00am" },
                new object[] { 11, "Exxon Mobil Corp", 68.1, -0.43, -0.64, "9/1 12:00am" },
                new object[] { 12, "General Electric Company", 34.14, -0.08, -0.23, "9/1 12:00am" },
                new object[] { 13, "General Motors Corporation", 30.27, 1.09, 3.74, "9/1 12:00am" },
                new object[] { 14, "Hewlett-Packard Co.", 36.53, -0.03, -0.08, "9/1 12:00am" },
                new object[] { 15, "Honeywell Intl Inc", 38.77, 0.05, 0.13, "9/1 12:00am" },
                new object[] { 16, "Intel Corporation", 19.88, 0.31, 1.58, "9/1 12:00am" },
                new object[] { 17, "International Business Machines", 81.41, 0.44, 0.54, "9/1 12:00am" },
                new object[] { 18, "Johnson & Johnson", 64.72, 0.06, 0.09, "9/1 12:00am" },
                new object[] { 19, "JP Morgan & Chase & Co", 45.73, 0.07, 0.15, "9/1 12:00am" },
                new object[] { 20, "McDonald\"s Corporation", 36.76, 0.86, 2.40, "9/1 12:00am" },
                new object[] { 21, "Merck & Co., Inc.", 40.96, 0.41, 1.01, "9/1 12:00am" },
                new object[] { 22, "Microsoft Corporation", 25.84, 0.14, 0.54, "9/1 12:00am" },
                new object[] { 23, "Pfizer Inc", 27.96, 0.4, 1.45, "9/1 12:00am" },
                new object[] { 24, "The Coca-Cola Company", 45.07, 0.26, 0.58, "9/1 12:00am" },
                new object[] { 25, "The Home Depot, Inc.", 34.64, 0.35, 1.02, "9/1 12:00am" },
                new object[] { 26, "The Procter & Gamble Company", 61.91, 0.01, 0.02, "9/1 12:00am" },
                new object[] { 27, "United Technologies Corporation", 63.26, 0.55, 0.88, "9/1 12:00am" },
                new object[] { 28, "Verizon Communications", 35.57, 0.39, 1.11, "9/1 12:00am" },
                new object[] { 29, "Wal-Mart Stores, Inc.", 45.45, 0.73, 1.63, "9/1 12:00am" }
            };

            this.Store1.DataBind();
        }
    }

    protected void ToXml(object sender, EventArgs e)
    {
        string json = GridData.Value.ToString();
        StoreSubmitDataEventArgs eSubmit = new StoreSubmitDataEventArgs(json, null);
        XmlNode xml = eSubmit.Xml;

        string strXml = xml.OuterXml;

        this.Response.Clear();
        this.Response.AddHeader("Content-Disposition", "attachment; filename=submittedData.xml");
        this.Response.AddHeader("Content-Length", strXml.Length.ToString());
        this.Response.ContentType = "application/xml";
        this.Response.Write(strXml);
        this.Response.End();
    }

    protected void btnTest_CLICK(object sender, EventArgs e)
    { 
        //To Do
    }
   
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Export Data from GridPanel into XML, Excel or CSV using a full PostBack - Ext.NET Examples</title>
    <link href="../../../../resources/css/examples.css" rel="stylesheet" type="text/css" />    
    
    <script type="text/javascript">
        var saveData = function() {
            GridData.setValue(Ext.encode(GridPanel1.getRowsValues({ selectedOnly: false })));
        };
    </script>
</head>
<body>
    <form id="Form1" runat="server">
        <ext:ResourceManager ID="ResourceManager1" runat="server" />
        
        <h1>Export Data from GridPanel into XML, Excel or CSV using a full PostBack</h1>
        
        <ext:Hidden ID="GridData" runat="server" />
        
        <ext:Store ID="Store1" runat="server">
            <Reader>
                <ext:ArrayReader>
                    <Fields>
                        <ext:RecordField Name="id" Type="Int" />
                        <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="M/d hh:mmtt" />
                    </Fields>
                </ext:ArrayReader>
            </Reader>
            <DirectEventConfig IsUpload="true" />
        </ext:Store>        
        
        <ext:GridPanel 
            ID="GridPanel1" 
            runat="server" 
            StoreID="Store1" 
            StripeRows="true"
            Title="Export Data" 
            TrackMouseOver="true"
            Width="600" 
            Height="350"
            AutoExpandColumn="Company">
            <ColumnModel ID="ColumnModel1" runat="server">
                <Columns>
                    <ext:Column ColumnID="Company" Header="Company" Width="160" DataIndex="company" />
                    <ext:Column Header="Price" Width="75" DataIndex="price">
                        <Renderer Format="UsMoney" />
                    </ext:Column>
                    <ext:Column Header="Change" Width="75" DataIndex="change" />
                    <ext:Column Header="Pct.Change" Width="75" DataIndex="pctChange" />
                    <ext:DateColumn Header="Last Updated" Width="85" DataIndex="lastChange" />
                </Columns>
            </ColumnModel>
            <SelectionModel>
                <ext:RowSelectionModel ID="RowSelectionModel1" runat="server" />
            </SelectionModel>
            <TopBar>
                <ext:Toolbar ID="Toolbar1" runat="server">
                    <Items>
                        <ext:ToolbarFill ID="ToolbarFill1" runat="server" />
                        
                        <ext:Button ID="Button1" runat="server" Text="To XML" AutoPostBack="true" OnClick="ToXml" Icon="PageCode">
                            <Listeners>
                                <Click Fn="saveData" />
                            </Listeners>
                        </ext:Button>                       
                      
                    </Items>
                </ext:Toolbar>
            </TopBar>
        </ext:GridPanel>  
        <br />
        <ext:Button ID="btnTest" runat="server" Text="Post Back" AutoPostBack="true" OnClick="btnTest_CLICK"></ext:Button>
    </form>
</body>
</html>
Thank you!