I need to make one grid column as the mandatory field.

I know how to make it with any separate control. E.g. I can type:

And I can use this Validator for the TextBox:

And it works. User can't send the form because he gets an error - the field is empty.

But I need to do the same with .

When I open "Edit columns" in Grid Wizard I can't see any property as "mandatory" or something like this.
And the code with RequiredFieldValidator doesn't work with a grid column. If I try to use it:

In this case, I have an error (look at screenshot)

Is there some method for grid column validation? Or it's impossible with a grid?

Hi,

I have a gridview with one combobox column that its populated depending of the value entered in column 1. The combobox column is populated as expected, but, if I save the values and open the record and click inside the combobox column the selected value in that row its not the value that comes from the db, it always select the first value of the combobox. And I need to get the saved selected value when I enter into edit mode.

My code

private void radGridView1_CellEditorInitialized(object sender, GridViewCellEventArgs e)
        {
            RadDropDownListEditor listEditor = this.radGridView1.ActiveEditor as RadDropDownListEditor;

            if (listEditor == null)
            {
                return;
            }

            RadDropDownListEditorElement editorElement = listEditor.EditorElement as RadDropDownListEditorElement;
            editorElement.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
            editorElement.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDownList;


            string item = radGridView1.CurrentRow.Cells[0].Value == null ? "" : radGridView1.CurrentRow.Cells[0].Value.ToString();

            var result = SqlClass.GetUOMByItem(item);
            editorElement.DataSource = null;
            editorElement.Items.Clear();
            editorElement.DataSource = result;
            editorElement.DisplayMember = "UOFM";
            editorElement.ValueMember = "UOFM";


            if (editorElement.Items.Count > 0)
            {
                editorElement.SelectedValue = null;
                editorElement.SelectedValue = this.radGridView1.CurrentCell.Value;

            }

        }

thanks for your help!!

I am using WinForm and export the radgridview to pdf. I want the top header row has some grey color to distinguish it as header row.  How to do that?  Can I change the TableBorderThickness to be less than 1?

ExportToPDF exporter = new ExportToPDF(this.radGridView1);
exporter.TableBorderThickness = 1;

Thanks.

Basically my problem is that I try to 23 columns groups for a grid view and it works and I add just 1 column grid view group and i have 
"An unhandled exception of type 'System.NullReferenceException' occurred in Telerik.WinControls.GridView.dll

Additional information: Object reference not set to an instance of an object." error. Is there any way to have in a grid view 24 columns groups or more?

Is there any maximum number of GridViewColumnGroup that you can assign to a RadGrid? I can add 23 groups (each contain subgroup) but when  I add the 24 group I get :
"An unhandled exception of type 'System.NullReferenceException' occurred in Telerik.WinControls.GridView.dll

Additional information: Object reference not set to an instance of an object."
I use the DLL from 2014. Any advice is helpful. I thank you much for your help and time.
My function is 
[QOUTE]ColumnGroupsViewDefinition view = new ColumnGroupsViewDefinition();

            // Group Header

            view.ColumnGroups.Add(new GridViewColumnGroup(""));
            view.ColumnGroups[0].Rows.Add(new GridViewColumnGroupRow());
            view.ColumnGroups[0].Rows[0].Columns.Add(dg_validare_antecalcul.Columns["pk_pr_cip"]);
            view.ColumnGroups[0].Rows[0].Columns.Add(dg_validare_antecalcul.Columns["Bifa"]);
            view.ColumnGroups[0].Rows[0].Columns.Add(dg_validare_antecalcul.Columns["Cip"]);
            view.ColumnGroups[0].Rows[0].Columns.Add(dg_validare_antecalcul.Columns["Program"]);
            view.ColumnGroups[0].Rows[0].Columns.Add(dg_validare_antecalcul.Columns["Reper"]);
            view.ColumnGroups[0].Rows[0].Columns.Add(dg_validare_antecalcul.Columns["Denumire Reper"]);
            view.ColumnGroups[0].ShowHeader = false;

            // CSTA

            GridViewColumnGroup oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTA";

            GridViewColumnGroup oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Pret de vanzare unitar";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTA_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTA_cip"]);

            dg_validare_antecalcul.Columns["CSTA_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTA_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // cost complet

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "COST COMPLET";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["cost_complet_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["cost_complet_cip"]);

            dg_validare_antecalcul.Columns["cost_complet_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["cost_complet_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            oGroup.ShowHeader = false;
            view.ColumnGroups.Add(oGroup);

            // CSTB

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTB";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Profit";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTB_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTB_cip"]);

            dg_validare_antecalcul.Columns["CSTB_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTB_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTC

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTC";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Ch. generale de administratie";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTC_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTC_cip"]);

            dg_validare_antecalcul.Columns["CSTC_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTC_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTD

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTD";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Costuri desfacere";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTD_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTD_cip"]);

            dg_validare_antecalcul.Columns["CSTD_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTD_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTE

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTE";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Cost de productie antecalculat-total";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTE_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTE_cip"]);

            dg_validare_antecalcul.Columns["CSTE_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTE_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTF

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTF";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Ch. indirecte af. Diviziei strategice";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTF_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTF_cip"]);

            dg_validare_antecalcul.Columns["CSTF_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTF_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTG

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTG";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Ch. indirecte af. Diviziei conducatoare";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTG_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTG_cip"]);

            dg_validare_antecalcul.Columns["CSTG_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTG_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTH

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTH";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Cost de productie antecalculat-propriu";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTH_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTH_cip"]);

            dg_validare_antecalcul.Columns["CSTH_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTH_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTI

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTI";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Ch. indirecte de sectie";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTI_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTI_cip"]);

            dg_validare_antecalcul.Columns["CSTI_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTI_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTJ

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTJ";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Materiale directe";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTJ_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTJ_cip"]);

            dg_validare_antecalcul.Columns["CSTJ_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTJ_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTK

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTK";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Nevoi proprii directe";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTK_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTK_cip"]);

            dg_validare_antecalcul.Columns["CSTK_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTK_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTL

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTL";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Chelt. cu scule";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTL_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTL_cip"]);

            dg_validare_antecalcul.Columns["CSTL_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTL_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTM

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTM";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Ch. transp-aprov.";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTM_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTM_cip"]);

            dg_validare_antecalcul.Columns["CSTM_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTM_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTN

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTN";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Manopera directa";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTN_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTN_cip"]);

            dg_validare_antecalcul.Columns["CSTN_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTN_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTO

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTO";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Indexare manop. directa ramasa";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTO_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTO_cip"]);

            dg_validare_antecalcul.Columns["CSTO_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTO_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTP

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTP";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Ch. salarii colaboratori";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTP_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTP_cip"]);

            dg_validare_antecalcul.Columns["CSTP_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTP_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTQ

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTQ";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "C.A.S. si alte fonduri af.(manop. directe+sporuri)";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTQ_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTQ_cip"]);

            dg_validare_antecalcul.Columns["CSTQ_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTQ_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTR

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTR";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "S.D.V. directe";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTR_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTR_cip"]);

            dg_validare_antecalcul.Columns["CSTR_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTR_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTS

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTS";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Alte costuri directe";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTS_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTS_cip"]);

            dg_validare_antecalcul.Columns["CSTS_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTS_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTT

            oGroup = new GridViewColumnGroup();
            oGroup.Text = "CSTT";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Colaborari directe";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTT_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTT_cip"]);

            dg_validare_antecalcul.Columns["CSTT_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTT_cip"].HeaderText = "CIP";

            oGroup.Groups.Add(oSubGroup);
            view.ColumnGroups.Add(oGroup);

            // CSTU
            //GridViewColumnGroup oGroup1 = new GridViewColumnGroup();
            //oGroup1.Text = "";

            GridViewColumnGroup oGroupU = new GridViewColumnGroup();
            oGroupU.Text = "CSTU";

            oSubGroup = new GridViewColumnGroup();
            oSubGroup.Text = "Utilitati directe";
            oSubGroup.Rows.Add(new GridViewColumnGroupRow());
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTU_unitar"]);
            oSubGroup.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTU_cip"]);

            dg_validare_antecalcul.Columns["CSTU_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTU_cip"].HeaderText = "CIP";

            oGroupU.Groups.Add(oSubGroup);
            //oGroup1.Groups.Add(oGroupU);
            view.ColumnGroups.Add(oGroupU);

            // CSTV

            GridViewColumnGroup oGroupV = new GridViewColumnGroup();
            oGroupV.Text = "CSTV";

            GridViewColumnGroup oSubGroupV = new GridViewColumnGroup();
            oSubGroupV.Text = "Corectii";
            oSubGroupV.Rows.Add(new GridViewColumnGroupRow());
            oSubGroupV.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTV_unitar"]);
            oSubGroupV.Rows[0].Columns.Add(dg_validare_antecalcul.Columns["CSTV_cip"]);

            dg_validare_antecalcul.Columns["CSTV_unitar"].HeaderText = "UNITAR";
            dg_validare_antecalcul.Columns["CSTV_cip"].HeaderText = "CIP";

            oGroupV.Groups.Add(oSubGroupV);
            //oGroup1.Groups.Add(oGroupV);
            //oGroup1.ShowHeader = false;
            //view.ColumnGroups.Add(oGroup1);
            view.ColumnGroups.Add(oGroupV);
            dg_validare_antecalcul.ViewDefinition = view;[/QUOTE]
Comment any of the of the grouping and fill grid works. With all the groups the fill grid gives error at the last line.  In my opinion it is because telerik controls think that there too many groups. 

Any help is appreciated and thank you for your time and effort.

I'm trying out the Hamburger menu, but when I click the 'Hamburger Icon" it begins to expand very slowly.  It's not as 'zippy' as in the demo... probably due to the complex control that is within the first menu item.

Anyway, I don't really want it to expand (I have it set to Compact) anyway.

Is there to prevent it from expanding when the 'hamburger icon' is clicked?

Hi again,

I'm new to working with column groups in Telerik.

I wanted to export my grid, but I can't show column group text in the output excel file.

I tried simple usage of exporter:

but I don't know how to customize it