Grouping columns programmatically in the Telerik RadGridView control for WinForms

Telerik RadGridView Grouped Columns

// http://docs.telerik.com/devtools/winforms/gridview/view-definitions/column-groups-view
// Grouped columns do not wrap header text; see http://www.telerik.com/forums/grouping-column-headers

var view = new ColumnGroupsViewDefinition();

var group = new GridViewColumnGroup("Reference Data");
view.ColumnGroups.Add(group);

var groupRow = new GridViewColumnGroupRow();
group.Rows.Add(groupRow);
groupRow.Columns.Add(gridItems.Columns["colRecordType"]);
groupRow.Columns.Add(gridItems.Columns["colFundingAgency"]);
groupRow.Columns.Add(gridItems.Columns["colMechanismID"]);
groupRow.Columns.ToList().ForEach(c => c.WrapText = true);
group.IsPinned = true;

group = new GridViewColumnGroup("");
view.ColumnGroups.Add(group);
groupRow = new GridViewColumnGroupRow();
group.Rows.Add(groupRow);
groupRow.Columns.Add(gridItems.Columns["colMechanismName"]);
groupRow.Columns.Add(gridItems.Columns["colPrimePartner"]);
groupRow.Columns.Add(gridItems.Columns["colTBDMechanism"]);
groupRow.Columns.Add(gridItems.Columns["colNewMechanism"]);
groupRow.Columns.Add(gridItems.Columns["colWorkingCapitalFund"]);
groupRow.Columns.ToList().ForEach(c => c.WrapText = true);

group = new GridViewColumnGroup("EE");
view.ColumnGroups.Add(group);
groupRow = new GridViewColumnGroupRow();
group.Rows.Add(groupRow);
groupRow.Columns.Add(gridItems.Columns["colGHP_State"]);
groupRow.Columns.ToList().ForEach(c => c.WrapText = true);

group = new GridViewColumnGroup("DD");
view.ColumnGroups.Add(group);
groupRow = new GridViewColumnGroupRow();

group.Rows.Add(groupRow);
groupRow.Columns.Add(gridItems.Columns["colGHP_USAID"]);
groupRow.Columns.ToList().ForEach(c => c.WrapText = true);

gridItems.ViewDefinition = view;

Note that newer versions of the RadGridView support design-time column groupings.