[MFC]CListCtrl > Selection change

 

There are a few notifications based on what's happening.

If you are selecting an item and nothing is selected yet, you will get one LVIF_STATE change notification: uNewState & LVIS_SELECTED. The newly selected item will be found at:

pNMListView->iItem

If an item is selected before you select a new object, you'll get three state changes:

First you will be informed that the previous item in focus is losing focus:

pNMListView->uOldState & LVIS_FOCUSED

Then you will be notified that the old item is being unselected:

pNMListView->uOldState & LVIS_SELECTED

Finally, you will get the new item selection state:

pNMListView->uNewState & LVIS_SELECTED

(again look at iItem for newly selected item)

So the pitfall we ran across is that, because item deselection results in two notifications, we were doing a lot of repetitive, sometimes detrimental, processing. What we ended up doing was only doing this processing for the 2nd message (pNMListView->uOldState & LVIS_SELECTED), and skipping the same processing after the loss of focus notification.