.NET Splash Screen Thread Problem

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

I am writing a VB.NET application that has a Splash screen.
..NET has autogenerated MyApplication Class.
In that class OnCreateSplashScreen calls a shared property to get the Splash
screen.
In this shared property I instantiate the splash screen object.

On this Splash screen I have a DevExpress MarqueeProgressBarControl or just
in short a progress bar control.

When I start up my application I get an exception: "Cross-thread operation
not valid"

When I debug this I notice something strange

1) .NET Calls OnCreateSplashScreen and in turn my shared property, that
instantiates the splash screen, on one thread.
2) .NET then shows the splash screen on a different thread!

I tried to show my SplashScreen form as a regular form (not as a splash
screen) and it worked fine. So my conclution is:

The progress bar I am using is obviously creating a timer that is associated
with a different thread than the progress control it self because it is
instantiated with one thread and shown with another. This timer is then
sending OnTimer to the progress bar and I get the exception.

So my questions is:
Why does .NET use two threads to Create and Activate a Splash screen?

I would think a form object should be instantiated and shown on the same
thread so I am surpriced that the .NET framework (or the VB framework) is
doing it this way.

Any suggestions how I can fix this? (removing the progress bar isn't an
option and turning off CheckForIllegalCrossThreadCalls isn't either)
 
Any suggestions how I can fix this? (removing the progress bar isn't
an option and turning off CheckForIllegalCrossThreadCalls isn't
either)
Click to expand...

Most probably you should take care of the update of the progress bar (I
am assuming, you are settings a new value of the progress bar).

The call "myProgressbar.Value = xyz" is maybe from another thread. So be
sure, you call it via myProgressBar.BeginInvoke(SomeMethod). And in this
method, you can set the new value of the progress bar.

hth
Markus
 
I am not calling the progress bar at all. It is a simular prograss bara as
when Windows XP starts up just going round and round until the Splash screen
closes.
 
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