You can assign an item to a group by specifying the group in the ListViewItem.#ctor constructor, by setting the ListViewItem.Group property, or by directly adding the item to the ListViewGroup.Items collection of a group. All items should be assigned to groups before they are displayed. Any items that are not assigned to a group will appear in the default group, which has the header label "DefaultGroup{0}". The default group is not contained in the ListView.Groups collection, and cannot be altered. It is primarily useful in debugging to ensure that all items have been properly added to groups.

An item can only be in one group at a time. You can change the group to which an item belongs by setting the ListViewItem.Group property at run time or by adding it to the ListViewGroup.Items collection of another group, which automatically removes it from the previous group.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Assembly Versions: 2.0.0.0
Since: .NET 2.0