Re: CListCtrl size at runtime

From:

"Tom Serface" <tom.nospam@camaswood.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 21 Nov 2008 14:09:04 -0800

Message-ID:

<DBEC7C4B-231D-4816-A9A0-1D3A3788BCE9@microsoft.com>

I think you figured out that calling LockWindowUpdate()/UnlockWindowUpdate()
was causing the problem on the desktop.

Now you just need a way to throttle your output so it doesn't get refreshed
so often.

Tom

"Gary" <Gary@discussions.microsoft.com> wrote in message
news:03A7D156-9842-48A5-924E-8F1F795FCB91@microsoft.com...

Sorry to buy you guys again.

am I doing something fundamentally wrong here ?

When I minimize my application and it is still running I see that all the
icons on my desktop are flickering.

All I am doing is this below when I receive a new data item:

  // Lock window update so that user doesn't see flicker as we populate
  mMyListCtrl.LockWindowUpdate();

  // Update the sentence list map
  mStringList[mItemsCount] = sentenceData;

  // Update the item count
  mItemsCount++;

  // Update the item count in virtual list control
  DWORD flags = LVSICF_NOINVALIDATEALL | LVSICF_NOSCROLL;
  mMyListCtrl.SetItemCountEx( mItemsCount, flags );

  // Scroll and ensure that the last item is always visible
  mMyListCtrl.EnsureVisible( mItemsCount - 1, FALSE );

  // Unlock window update
  mMyListCtrl.UnlockWindowUpdate();

Thanks,
Gary

"Gary" wrote:

Just tried using LockWindowUpdate and UnLockWindowUpdate() and they seem
to
do the trick along with the double buffering style. A lot less
flickering.

I am doing something wrong or it is fine to use double buffering and lock
and unclock window update when I am updating my internal data storage and
updating the count in the list control using ??

mMyListCtrl.LockWindowUpdate()

mMyListCtrl.SetItemCountEx( mItemsCount, flags );

mMyListCtrl.UnLockWindowUpdate()

Thanks,
Gary

"Gary" wrote:

Using this reduces the flicering but still it is there.

mMyListCtrl.SendMessage( LVM_SETEXTENDEDLISTVIEWSTYLE,
LVS_EX_DOUBLEBUFFER,
LVS_EX_DOUBLEBUFFER);

Thanks,
Girish

"Gary" wrote:

Thanks a lot Tom, appreciated.

I should be using ON_NOTIFY as you suggested and it does seem to
work.
Sorry about ON_GETDISPINFO, it was just a typo, I meant
LVS_GETDISPINFO.

One thing I observed was that the list control flickers.
I am using EnsureVisible() so that the last time is visible and it is
automatically scrolled.

Is it possible to reduce the flickering ?

Thanks,
Gary

"Tom Serface" wrote:

Hi Gary,

I sent you email with what I think is going on in your process. If
so it
will be easy to fix. I think you need to use ON_NOTIFY() rather
than
ON_NOTIFY_REFLECT() in this case. I don't think there is such a
thing as
ON_GETDISPINFO, but you would use the form:

ON_NOTIFY(LVN_GETDISPINFO, IDC_LIST1, OnGetItemInfo)

The control on the dialog will notify the dialog (where the handler
lives)
when it needs data to display in a line.

As I mentioned in my email you can also add the handler in the
properties
window to have it set all this up for you. You just have open the
dialog,
select it, then click the little lightning bolt icon on the top of
the
properties window. From there you can open the tree for the list
control
and hook into all kinds of notification messages and it will set up
the code
for you (at least the functions, you have to fill in what you want
to do in
the functions of course).

FWIW, once you have this set up it will be really easy for you to
extend it
and use this idea in other programs. It's just doggone learning
curve
thing.

Hope that helps,

Tom

"Gary" <Gary@discussions.microsoft.com> wrote in message
news:CDD2142F-71A4-41F8-AF94-DC531222AEC3@microsoft.com...

I guess my OnGetItemInfo() function corresponding to the
ON_GETDISPINFO
macro
is never geting called ?

If so then why would that be happening ?

Thanks,
Gary

"Gary" wrote:

Ok, resolved the issue by setting the Owner Data to "true"
through the
Properties window, I guess that is the way to do it, setting
extended
style
won't work.

But now my virtual list control doesn't display anything.

I did add a method corresponding to the macro:

ON_NOTIFY_REFLECT( LVN_GETDISPINFO, OnGetItemInfo )

Do I need to do anything else ?