This macro prepares a list-view control for adding a large number of items. You can use this macro or send the LVM_SETITEMCOUNT message explicitly.
If the list-view control was created without the LVS_OWNERDATA style, this macro causes the control to 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.
If the list-view control was created with the LVS_OWNERDATA style (a virtual list view), the ListView_SetItemCountEx macro should be used.
In Windows CE 2.0 and later, if the list-view control is a virtual list view (has the LVS_OWNERDATA style), use the ListView_SetItemCountEx macro instead.
Related message: LVM_SETITEMCOUNT