Actually, it’s the underlying Windowing subsystem that has thread affinity, ActiveX controls being STA bound was a reflection of the requirement that all window procedure processing is performed on the thread that created the window.
So it’s a Windows thing that means that you have Winforms thread affinity. Now, it is theoretically possible for all members of all classes in Winforms to have the InvokeRequired check and perform the marshalling internally. However, the overhead of this would be huge in the face of most windowing code is accessed from the owning thread anyway. Regards Richard Blewett DevelopMentor > -----Original Message----- > From: Moderated discussion of advanced .NET topics. [mailto:ADVANCED- > [EMAIL PROTECTED] On Behalf Of Thomas Tomiczek > Sent: 23 February 2004 07:17 > To: [EMAIL PROTECTED] > Subject: Re: [ADVANCED-DOTNET] Thread with message pump (UI thread) > > There is no cleaner or different way for one simple reason: > > Compatibility with ActiveX components. > > They require STA and they limit the whole thing to this type of message > pump. > > Now, dropping them is not an option, too. A lot depends on this model. > > Thomas Tomiczek > THONA Software & Consulting Ltd. > (Microsoft MVP C#/.NET) > (CTO PowerNodes Ltd.) > > > -----Original Message----- > > From: Moderated discussion of advanced .NET topics. > > [mailto:[EMAIL PROTECTED] On Behalf Of Jade Burton > > Sent: Montag, 23. Februar 2004 03:12 > > To: [EMAIL PROTECTED] > > Subject: Re: [ADVANCED-DOTNET] Thread with message pump (UI thread) > > > > As a sidebar to the topic of threads and message pumps, am I > > the *only* person in the world who wishes there was greater > > *cohesion* and > > *transparency* between WinForms' and worker threads? > > > > Why, in 2004, do programmers have to call some hokey > > form.Invoke(SetSomeControlMethod, blah) in order to update > > something on the form from within a worker thread? > > > > When I first saw .NET I had hoped that a cleaner model had > > been adopted by WinForms, but alas I was disappointed to see > > it's but another Windows wrapper. > > > > I'm not sure there's a clean alternative to having a message > > pump drive the UI (maybe there is?), but there *must* be a > > cleaner way than the current segregated STA-MTA ideology > > which has weasled its way into .NET? For example, why can't > > I just call form.SetSomeControlMethod and have it update > > inline, without any windows messages being sent? (And why > > can't I create a modal dialog from within a worker that > > simply blocks until the user clicks OK, rather than using > > another message loop etc?) > > > > Or are we stuck with what I would regard as a system that > > requires the programmer to write (and - ugh - think about) > > "non-business logic" plumbing code... > > > > Jade Burton > > > > -----Original Message----- > > From: Moderated discussion of advanced .NET topics. > > [mailto:[EMAIL PROTECTED] Behalf Of > > Shawn A. Van Ness > > Sent: Saturday, 21 February 2004 10:48 AM > > To: [EMAIL PROTECTED] > > Subject: Re: [ADVANCED-DOTNET] Thread with message pump (UI thread) > > > > > > Call Application.Run (or even Application.DoEvents) do > > establish a message queue for your secondary thread. > > > > A better answer: You should not be performing any > > long-blocking operations on your main UI thread. This rule > > goes right up there alongside "thread that creates the window > > services the window". > > > > (By "it is difficult to free the main thread" I assume you > > mean your main UI thread is performing some long-blocking > > operation -- like socket i/o, or calculating pi to 3000 > > decimal places, or what have you. Don't do that.) > > > > -Shawn > > http://www.windojitsu.com/ > > > > On Fri, 20 Feb 2004 13:35:57 -0500, Aman Jain > > <[EMAIL PROTECTED]> wrote: > > > > >Hi Everybody, > > > > > >The alarm manager in my Windows Forms application has a > > alarm control > > >(User control) that is used to display errors. > > >This is created on the Main thread. Whenever any calls are > > made on this > > >control to display errors, we take care to switch to the Main thread > > >(windows principle: thread that creates the window services > > the window) > > >using > > > > > > > > > private void OnAlarmMessageReceived(AlarmMessage msg) > > > { > > > if(InvokeRequired) // Pass on to GUI thread > > > { > > > BeginInvoke(new > > >AlarmMsgReceivedHandler(OnAlarmMessageReceived), new > > Object[] { msg } ); > > > return; > > > } > > > // whatever needs to be done > > > } > > > > > >This works fine but with the requirement that the main > > thread is free. > > >Now, there are many situations where it is difficult to free > > the main > > >thread but there are errors that need to be displayed. > > >What I need is a UI thread that remains alive during the > > application > > >lifetime on which I can create and service the alarm window. In the > > >managed world (using C#) , how do we create a thread with a message > > >pump as opposed to a worker thread ? > > > > > >Any help is greatly appreciated. > > > > > >Thanks in advance, > > >Aman > > > > > > > > >=================================== > > >This list is hosted by DevelopMentor(r) > > http://www.develop.com Some .NET > > >courses you may be interested in: > > > > > >NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles > > >http://www.develop.com/courses/gaspdotnetls > > > > > >View archives and manage your subscription(s) at > > >http://discuss.develop.com > > =================================== > > This list is hosted by DevelopMentor(r) http://www.develop.com > > Some .NET courses you may be interested in: > > > > NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles > > http://www.develop.com/courses/gaspdotnetls > > > > View archives and manage your subscription(s) at > > http://discuss.develop.com > > > > -- > > This message has been scanned for viruses and dangerous > > content by MailScanner, and is believed to be clean. > > > > > > -- > > This message has been scanned for viruses and dangerous > > content by MailScanner, and is believed to be clean. > > > > =================================== > > This list is hosted by DevelopMentor(r) http://www.develop.com > > Some .NET courses you may be interested in: > > > > NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles > > http://www.develop.com/courses/gaspdotnetls > > > > View archives and manage your subscription(s) at > > http://discuss.develop.com > > > > > > =================================== > This list is hosted by DevelopMentor. http://www.develop.com > Some .NET courses you may be interested in: > > NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles > http://www.develop.com/courses/gaspdotnetls > > View archives and manage your subscription(s) at > http://discuss.develop.com > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.593 / Virus Database: 376 - Release Date: 20/02/2004 > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.593 / Virus Database: 376 - Release Date: 20/02/2004 =================================== This list is hosted by DevelopMentor® http://www.develop.com Some .NET courses you may be interested in: NEW! Guerrilla ASP.NET, 17 May 2004, in Los Angeles http://www.develop.com/courses/gaspdotnetls View archives and manage your subscription(s) at http://discuss.develop.com
