Some of the eagle-eyed amongst you will spot this as a direct follow on from
my earlier post about critical timing in .NET.

I want to use a ListView to display my output (instead of the sluggish
RichTextBox), but it flickers madly when I update it. There have been
numerous posts about this, but I have found no solution. Enabling
double-buffering does not seem to help, so has anyone any idea how it can be
done?

TIA

Charles

Charles,

Did you already look about the messages from our newsgroup flicker (not in
the Dutch meaning)  expert  Mick

http://groups-beta.google.com/group/microsoft.public.dotnet.languages.vb/browse_frm/thread/e402f82c888c902a/120dce829000245a?q=mick+flicker+listview&rnum=1#120dce829000245a

Cor

Charles,

Forget it, I saw listview in the thread however it was not as your problem.

I find it needles to tell to you that there is a standard option for that,
because I assume that you know that and does not work for you as you expect.

Cor

Use the .BeginUpdate, .EndUpdate methods of the ListView class.



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Hi David

Thanks for the response. Sadly that does not help, though. I already have it
in place. Every time the EndUpdate method is called the control refreshes,
hence the flicker. I am adding a row every 200 ms, say, and the flicker is
especially bad.

Charles


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Ok chaps. I have the answer.

It would seem that I had mis-read the purpose of the BeginUpdate/EndUpdate
methods; like many before me I suspect.

These commands actually make the update occur, thus causing the flicker not
reducing it.

I tried all sorts of things, from double-buffering to sub-classing and
filtering the WM_ERASEBKGND message. I even tried LockWindowUpdate from one
of our esteemed number from way back. None of these worked.

The answer is as simple as calling the Update method after adding each item.

<code>
        With ListView1
            Dim lvi As New ListViewItem("Some really important information")

            lvi.ForeColor = Color.Green

            .Items.Add(lvi)

            .EnsureVisible(.Items.Count - 1)

            .Update()
        End With
</code>

The result is a silky smooth update, with no flicker. No sub-classing,
filtering, or double-buffering required.

Can you tell I'm happy :-))

Charles


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