Dynamically Creating a GridTemplateColumn

[Jordan Parfitt]

I have a radgrid in my ASPX page. Depending on what the user asks for add add columns to this grid dynamically.

One of the columns is a GridTemplateColumn. I add an image to this column.

It all loads properly on the first grid bind, however if I click the view next page feature on the rad grid this column disappears.

Has anyone had experience with this?

Thanks,
Jordan Parfitt

[Jordan Parfitt]

After further review my column seems to dissappear on all postbacks - anyone know why?

[Vladimir]

Hi Jordan,

When the grid declaration is on the page you should create columns similar to this example:
http://www.telerik.com/demos/aspnet/prometheus/Grid/Examples/Programming/GroupBy/DefaultCS.aspx

Creating template column in this scenario is not supported - you can create the entire grid dynamically similar to this example:
http://www.telerik.com/demos/aspnet/prometheus/Grid/Examples/Hierarchy/DefiningStructure/DefaultCS.aspx

[Jordan Parfitt]

So am I to understand that it is not possible to dynamically create a GridTemplateColumn?


Thanks,

Jordan

[Konstantin Petkov]

Hello Jordan,

You can create GridTemplateColumns dynamically as well. I believe you will find the following article helpful (look at the "Creating template columns programmatically" part):

http://www.telerik.com/help/radcontrols/aspnet-ajax/?grdProgrammaticCreation.html

Sincerely yours,
Konstantin Petkov
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Jordan Parfitt]

In the example you just showed me... as well as in mine, all the images/textboxes/chechbox/etc. are no longer visible on post-back. Why is this and is there a way to prevent it?

Thanks,
Jordan

        private void CreateTemplateColumn(RadGrid Grid, string datafield, string headertext, int index)
        {
            GridTemplateColumn tmpColumn = new GridTemplateColumn();
            Grid.MasterTableView.Columns.AddAt(index, tmpColumn); //Add column before setting properties
            tmpColumn.HeaderText = headertext;
            tmpColumn.UniqueName = datafield;
            tmpColumn.DataField = datafield;
            tmpColumn.ItemTemplate = new Flags();
        }

    public class Flags : ITemplate
    {
        protected Image imgFlag;

        public void InstantiateIn(System.Web.UI.Control container)
        {
            imgFlag = new Image();
            imgFlag.ID = "imgFlag";
            imgFlag.ImageUrl = "~/images/document.gif";
            imgFlag.DataBinding += new EventHandler(imgFlag_DataBinding);
            container.Controls.Add(imgFlag);
        }
    }

[Jordan Parfitt]

If it makes a difference I am adding my Grid on the ASPX, then adding columns dynamically.


                    <td valign="top">
                        <asp:Label ID="lblquad1" runat="server" Font-Bold="true"></asp:Label>
                        <radG:RadGrid ID="rgQuad1" runat="server" GridLines="None" AutoGenerateColumns="false" Skin="Office2007" AllowSorting="True" AllowPaging="true" OnDataBound="rgQuad1_OnDataBound" OnNeedDataSource="rgQuad1_OnNeedDataSource" OnItemCommand="rgQuad1_ItemCommand" EnableViewState="true">
                               <MasterTableView PageSize="25" CommandItemDisplay="Bottom">     
                                    <CommandItemTemplate>
                                        <asp:ImageButton ID="btnExcel" ImageUrl="../images/excel.png" ToolTip="Export to MS Excel" Visible='<%# !rgQuad1.MasterTableView.IsItemInserted %>' runat="server" CommandName="Excel" OnDataBinding="btnExcel1_OnDataBinding" OnClientClick="javascript:ExportToExcel(1)"/>
                                    </CommandItemTemplate>
                                    <ExpandCollapseColumn Visible="False"><HeaderStyle Width="19px" /></ExpandCollapseColumn>
                                    <RowIndicatorColumn Visible="False"><HeaderStyle Width="20px" /></RowIndicatorColumn>
                                </MasterTableView>
                        </radG:RadGrid>
                    </td>

[Kiara]

I read the documentation topic linked in the previous post and it states that mixes load of columns is not supported by the Telerik grid. Moreover, it indicates that when generating template columns you have to build your grid entirely programmatically on PageInit and add the columns to the Columns collection after you set their properties.

Having in mind these details, correct your code to see how it goes.

Kiara

[Jordan Parfitt]

When I built it all programmatically instead of having the radgrids on the ASPX it worked fine. Thanks