Very slow rendering of tabs

Hello,
>
I have a small application which acts like a wizard with 5 steps. I
use a tab control, and 'back' and 'next' buttons to switch between the
5 tabs (1 tab page for each step). The components on each tab are very
light (mostly labels and input fields) and my C# code (the actual
program logic) is well optimized. I also use multi threading to
separate the UI from the core of the app.
>
The rendering of the each tab page when I click 'next' is unacceptably
slow even on a very fast machine. Each time a new tab page becomes
active, the screen flickers a lot in the transition and it takes a few
moments (my guess is half a second). Clicking on the tab page
directly, instead of using a button, doesn't affect the speed.
>
Is there a way to speed up this thing or are Windows Forms used this
way bound to be very slow? All I need is a responsive UI. Is there an
easy way to preload them or pre-paint the pages at load time? It looks
like the repaint when a tab page becomes active, is what takes most of
the execution time.
>
Thank you.
-- Ruby
>

Hi,
>
You will have to post some code to see how you are creating your tabs.
You are not creating the controls when you show the tab are you?

On Oct 2, 1:52 pm, "Ignacio Machin \( .NET/ C# MVP \)" <machin TA
laceupsolutions.comwrote:>
Hi Ignacio,
>
the controls are all created at design time. The only thing that
happens at run time is the addition of the page and the selection of
the active tab. When one clicks on 'next' the code invoked is the
following:
>
private void OpenNext()
{
TabPage currentOne = mainTab.SelectedTab;
switch (current.Text)
{
case "Step A":
if (!mainTab.TabPages.Contains(PageB))
mainTab.TabPages.Add(PageB);
mainTab.SelectedTab = PageB;
break;
case "Step B":
if (!mainTab.TabPages.Contains(PageC))
mainTab.TabPages.Add(PageC);
mainTab.SelectedTab = PageC;
break;
//...
}
}
>
I tried to select a tab that was already added and it doesn't change
the speed.
>
Further investigation shows that this flickering effect is no longer
there and the pages load instantly if I remove the background image
that is loaded for each tab. Is there a way to have it loaded very
fast?
>
Thanks.
-- Ruby
>

Further investigation shows that this flickering effect is no longer
there and the pages load instantly if I remove the background image
that is loaded for each tab. Is there a way to have it loaded very
fast?