Rapid Open/Close of a Windows Form

[Bill Kinnersley]

I have a Windows Form with a very large ListView, about 10,000 items. There
is a very significant delay each time the form is opened (ShowDialog) or
closed (Hide). The ListView has not been modified in between, but for some
reason the graphics associated with it must be getting destroyed at each
Hide and re-created at each Show. Is there any way to avoid this, and hence
avoid the lengthy pause?

Thanks!

[Bob Powell [MVP]]

Not really. ListBox is based on the old ListView control and has
limitations.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Ramuseco Limited .NET consulting
http://www.ramuseco.com

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/faqmain.htm

All new articles provide code in C# and VB.NET.
Subscribe to the RSS feeds provided and never miss a new article.

"Bill Kinnersley" <bi***@eecs.ku.edu> wrote in message
news:11*************@corp.supernews.com...

I have a Windows Form with a very large ListView, about 10,000 items.
There is a very significant delay each time the form is opened (ShowDialog)
or closed (Hide). The ListView has not been modified in between, but for
some reason the graphics associated with it must be getting destroyed at
each Hide and re-created at each Show. Is there any way to avoid this, and
hence avoid the lengthy pause?

Thanks!

[Bill Kinnersley]

All I want to do is trick Windows into not disposing the control's graphics
between Shows. Something like double buffering? I wouldn't think that a
way to do this would depend on the particular control involved, but maybe
it does. Is there another grid control that would make it possible?

"Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> wrote in message
news:Oo**************@TK2MSFTNGP12.phx.gbl...

Not really. ListBox is based on the old ListView control and has
limitations.
--
Bob Powell [MVP]
Visual C#, System.Drawing

"Bill Kinnersley" <bi***@eecs.ku.edu> wrote in message
news:11*************@corp.supernews.com...

I have a Windows Form with a very large ListView, about 10,000 items.
There is a very significant delay each time the form is opened
(ShowDialog) or closed (Hide). The ListView has not been modified in
between, but for some reason the graphics associated with it must be
getting destroyed at each Hide and re-created at each Show. Is there any
way to avoid this, and hence avoid the lengthy pause?

Thanks!

[Bill Kinnersley]

Well, I have a workaround. Noting that Hide produces a long delay,
but changing Visible does not, we do the following -- Form A ShowDialogs a
teeny little Form B, which makes Form C (containing the big ListView)
visible. When done, we make C not visible, then Hide B, passing the results
back along the way to A. This is quite a kludge, and I find it hard to
believe there is not a better way.

Thanks,
Bill K.

"Bill Kinnersley" <bi***@eecs.ku.edu> wrote in message
news:11*************@corp.supernews.com...

All I want to do is trick Windows into not disposing the control's
graphics
between Shows. Something like double buffering? I wouldn't think that a
way to do this would depend on the particular control involved, but maybe
it does. Is there another grid control that would make it possible?

"Bob Powell [MVP]" <bob@_spamkiller_bobpowell.net> wrote in message
news:Oo**************@TK2MSFTNGP12.phx.gbl...

Not really. ListBox is based on the old ListView control and has
limitations.
--
Bob Powell [MVP]
Visual C#, System.Drawing

"Bill Kinnersley" <bi***@eecs.ku.edu> wrote in message
news:11*************@corp.supernews.com...

I have a Windows Form with a very large ListView, about 10,000 items.
There is a very significant delay each time the form is opened
(ShowDialog) or closed (Hide). The ListView has not been modified in
between, but for some reason the graphics associated with it must be
getting destroyed at each Hide and re-created at each Show. Is there any
way to avoid this, and hence avoid the lengthy pause?

Thanks!