At the heart of every grid is a DataGridContext that provides contextual information on, and access to, the items they contain and acts as a hub through which all interactions with the grid pass. The grid that is the source of the context can be retrieved through a context's DataGridControl property.

Each context exposes an Items property that represents the collection view that was used to generate the content of the context and whose type depends on the source of the context. Items will be an ItemCollection.

Context Life Cycle

The data-grid context of a grid always exists. The current context, whose CurrentItem and CurrentColumn properties correspond to the GlobalCurrentItem and GlobalCurrentColumn of its parent grid, can be retrieved through the parent grid's CurrentContext property or by checking a context's IsCurrent property. If items are selected in the current context, they can be retrieved through the context's SelectedItems collection and will also be part of the parent grid's GlobalSelectedItems collection. The contexts in which items are selected can be retrieved through the SelectedContexts property.

Retrieving a Context

In addition to the current and selected contexts, which can be retrieved through a grid's CurrentContext and SelectedContexts properties, the data-grid context of any container can also be retrieved using the DataGridControl.DataGridContext attached property. 

Manipulating Context Items

The items that are contained in a context, be they groups, details, data items, or any items contained in the headers or footers of the grid or detail that is the source of the configuration, can be manipulated through their context.

A context's BeginEdit method will place the context's current item or a specific item, which must be part of the context, in edit mode. Modifications made to edited item will be committed when EndEdit is called or discarded when CancelEdit is called (see Editing Data topic).

The CollapseGroup, ExpandGroup, and ToggleGroupExpansion methods can be used to modify the expansion state of a specific group while the IsGroupExpanded method can be used to determine if a particular group is expanded. Like the BeginEdit method, the specified data item or group must be part of the context or an exception will be thrown.