CXTTreeCtrl mutli selection problems

We are using the CXTTreeCtrl in multi-select mode and have found that tracking the items being selected and deselected using the TVN_SELCHANGED message does not work when selecting multiple items using CTRL and SHIFT. The visual appearance of the trees selection is correct but it is impossible to track the changes.

I have attached a modified TreeCtrl sample that helps show the problem (use the multiselect tree) - message boxes will popup to show which items are being selected and deselected.

uploads/20070817_102009_TreeCtrl_Sample.zip

Test scenario 1:

1. Select item 1
   
1. notified that item 1 is selected
2. CTRL select item 2
   
1. notified that item 1 is deselected
2. notified that item 2 is selected

Test scenario 2:

1. Select item 1
   
1. notified that item 1 is selected
2. SHIFT select item 3
1. notified that item 1 is deselected
2. notified that item 2,3 are selected

Both Vista and XP show similar behaviour (although on Vista the tree seems to send more TVN_SELCHANGED notifications).

Hi,

I did find a way to get around this by filtering out focus changes in OnSelectionChange.

BOOL CMyTreeCtrl::OnSelectionChange (NMHDR* pNMHDR, LRESULT* pResult)
  {
  NMTREEVIEW* pTv;
  pTv = (NMTREEVIEW*)pNMHDR;
  *pResult = 0;

  HTREEITEM hFocusedItem = GetFocusedItem ();
  HTREEITEM hNewItem = pTv->itemNew.hItem;
  HTREEITEM hOldItem = pTv->itemOld.hItem;
  if ( !hFocusedItem && hOldItem && !hNewItem )
    {
    // then me must have a Focus change and we don't want to process this as a selection change.
    }
  else
    {
    if (hNewItem)
      {
       CMyTreeItem* pData = GetMyTreeItem (hNewItem);
       //select item
      }
    if (hOldItem)
      {
      CMyTreeItem* pData = GetMyTreeItem (hOldItem);
      // deselect item
      }
    }

Hope this helps