Use Count to determine the number of items displayed by the list view. Count provides an upper bound when iterating through the individual TListItem objects in the Item property array. 

Set the Count when the list view's OwnerData property is false to make the control allocate its internal data structures for the specified number of items. This prevents the control from having to allocate the data structures every time an item is added. 

Set the Count when the list view's OwnerData property is true to set the virtual number of items that the control contains. 

Item