property Grid.AllowGroupBy as Boolean
Indicates whether the control supports Group-By view.

Boolean A Boolean expression that specifies whether the user can group the items.
By default, the AllowGroupBy property is False. Set the  AllowGroupBy property on True, to allow the user to group the items by dragging the column's header to control's sort bar. The SortBarVisible property specifies whether the control's sort bar is visible or hidden. If the control's sort bar is visible, the user can drag and drop columns to it, so the column get sorted and items grouped. The AddGroupItem event is fired when a new grouping items is added to the control's list. You can use the AddGroupItem event, to add headers or footers during grouping, customize the aggregate formula to be displayed on different columns, while dropping a column to the sortbar. The Column.AllowGroupBy property may be used to prevent grouping a specific column. The AllowSort property indicates whether the user can sort a column by clicking the column's header. The IsGrouping property specifies whether the control is grouping/ungrouping items. During grouping, the control keeps the items indentation, in other  words, a child item will be a child after or before grouping. The LayoutChanged event is fired when the user changes the layout of the control, including dragging a column to the sort bar. The SortBarColumnsCount property indicates the number of the columns being grouped. The SortBarColumn property indicates the column being sorted giving its position in the sort bar. The Group/Ungroup method groups or ungroup the control's list. For instance, you can remove the grouping items, by calling the Ungroup method. The GroupByTotalField property determines the formula to be applied to the column when it gets grouped. The GroupByFormatCell property determines the format of the cell to be displayed in the grouping item, when the column gets sorted.

The following movies show how Group-By works: 

In case you need more than a Group-By feature, you should check the Exontrol's eXPivot. The Exontrol's eXPivot tool is our approach to provide data summarization, as a pivot table. A pivot-table can automatically sort, count, total or give the average of the data stored in one table or spreadsheet. The user sets up and changes the summary's structure by dragging and dropping fields graphically. The eXPivot component lets the user changes its visual appearance using skins, each one providing an additional visual experience that enhances viewing pleasure. Skins are relatively easy to build and put on any part of the control.

The following screen shot shows the control grouping the orders and details by country ( the items keep their children when the control performs the grouping/ungrouping ):

The following screen shot shows the control grouping the orders by country:

The AllowGroupBy property/feature has no effect if: