I want to execute some code when the user selects a row in a CListCtrl (report view, I don't care about the other viewing modes).
How do I catch this event? is there some message I can map or a method like "OnSelectionChanged" or something like that?
Also try:
BEGIN_MESSAGE_MAP(cDlgRun, CDialog)
ON_NOTIFY(LVN_ITEMCHANGED, IDC_LIST2, OnItemchangedList2)
END_MESSAGE_MAP()
/* ... */
void cDlgRun::OnItemchangedList2(NMHDR* pNMHDR, LRESULT* pResult)
{
NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
if ((pNMListView->uChanged & LVIF_STATE)
&& (pNMListView->uNewState & LVIS_SELECTED))
{
// do stuff...
}
}
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.
djeidot is right on.
I just want to add that there is no OnSelectionChanged() because the ListView supports multi-selection (although this can be disabled). Therefore, a single-selection listview will send you two events: Old item unselected AND New item selected.
On my Visual Studio 2010, the visual editor declares a callback in the dialog header file like this:
afx_msg void OnLbnSelchangeListOnvif();
and in the source file:
BEGIN_MESSAGE_MAP(CDialogOnvif, CDialog)
ON_LBN_SELCHANGE(IDC_LIST_ONVIF, &CDialogOnvif::OnLbnSelchangeListOnvif)
END_MESSAGE_MAP()
void CDialogOnvif::OnLbnSelchangeListOnvif()
{
// do stuff...
}
来源:https://stackoverflow.com/questions/1462895/how-to-detect-a-clistctrl-selection-change