GridHyperLinkColumn Value dissappeared when RadGrid is rebind

[illumination]

I have a Radgrid that the first column is created with:

        <telerik:RadGrid ID="RadGrid1" runat="server" AllowFilteringByColumn="True" Width="100%"
            AllowSorting="True" GridLines="None" Skin="Web20" OnNeedDataSource="RadGrid1_NeedDataSource"
             OnSortCommand="RadGrid1_SortCommand" OnItemCreated="RadGrid1_ItemCreated" AllowPaging="true"
             AutoGenerateColumns="False" >
<MasterTableView >
<Columns>
                   <telerik:GridHyperLinkColumn DataNavigateUrlFields="EMPLOYEEID" DataNavigateUrlFormatString="~/Search.aspx?EMPLOYEEID={0}"
                        DataTextField="EMPLOYEEID" HeaderText="ID" AllowFiltering="true" FilterControlWidth="35px" UniqueName="EMPLOYEEID">
                        <HeaderStyle ForeColor="White" Font-Names="Arial Narrow" Font-Size="Small" />
                        <ItemStyle Font-Names="Arial Narrow" Font-Size="Small" Font-Bold="True" Font-Underline="True" />
                    </telerik:GridHyperLinkColumn>
                    <telerik:GridBoundColumn DataField="IDENTIFIER" HeaderText="IDENTIFIER" SortExpression="IDENTIFIER"
                        UniqueName="IDENTIFIER">
                    </telerik:GridBoundColumn>
.....
</Columns>
<PagerStyle Mode="NumericPages" PageButtonCount="10" />
</MasterTableView>

The problem I am having is:
Radgrid1 is generated on page load and it is working correctly... appeared with the first column with hyperlink ability. Then I click other grid control such as next page or filtering... then the ID dissappeared. so the first column only showing me dashes (-).
Can anybody help me on how to fix this problem?
Thank you.

[Vlad]

Hi illumination,

According to posted code RadGrid is declared on page however you stated that "Radgrid1 is generated on page load" -  can you clarify this confusion?

Regards,
Vlad
the Telerik team

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[illumination]

Vlad,
Thank you for the quick reply. the grid is loaded after the user click one of the radiobutton option and then click search button. sorry for the confusion.

[Princy]

Hi illumination,

When you perform Search operation the Grid is populated in the button's click event. After that when you perform any operation that causes a PostBack the Grid will be empty since its DataSource is not set in the succeeding PostBacks.

   So in order to retain the Search result while Paging/Sorting etc store the filtered result to a ViewState in the button click event and then in the NeedDataSource event populate the Grid again from the ViewState.  NeedDataSource  event will be fired each and every time a Grid operation is performed. Here is a Sample code:

ASPX:

   <telerik:RadGrid ID="RadGrid1" runat="server"  AllowPaging="true" PageSize="5"   ShowGroupPanel="true" OnNeedDataSource="RadGrid1_NeedDataSource">
            <MasterTableView CommandItemDisplay="Top">
            </MasterTableView>
            <ClientSettings AllowDragToGroup="true" AllowColumnsReorder="true" >
            </ClientSettings>
        </telerik:RadGrid>

  <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Filter" />

CS:

  protected void RadGrid1_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
    {
        if (ViewState["GridData"] != null)
        {
            RadGrid1.DataSource = ViewState["GridData"];
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
         string connectionstring = "Data Source=MyData; Initial Catalog=NorthWind;User ID=***; Password=*****";
         SqlConnection conn = new SqlConnection(connectionstring);
         SqlCommand cmd = new SqlCommand();
             conn.Open();
            SqlDataAdapter adp = new SqlDataAdapter("select * from  Products", conn);
            DataTable dt = new DataTable();
            adp.Fill(dt);
            ViewState["GridData"] = dt;

            if (ViewState["GridData"] != null)
            {
                RadGrid1.DataSource = ViewState["GridData"];
            }
            RadGrid1.DataBind();
            conn.Close();
    }

Thanks
Princy