STA's and MTA's

[Razzie]

Hey all,

I somewhat know of the differences between STA's and MTA's - theoratically.
However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a STA
by default. I can change this to MTA if I want to. But, what is the use of
this? Is it bad? Good? Can anyone give me a practicle example of when you
should use STA and when MTA?

Cheers,

Razzie

[Richard Blewett [DevelopMentor]]

It is generally a bad idea as there are a nunber of UI things that use COM as a backbone. This will expect (due to the thread sensitivity of UI code) to have the code accessed from an STA thread. If you have any activeX controls on your form (you may have them unknowingly by using a 3rd party control) or you want to use OLE drap and drop (which won't be initialized if you use MTAThread) there will be issues.

Regards

Richard Blewett - DeveloopMentor
http://staff.develop.com/richardb/weblog

Hey all,

I somewhat know of the differences between STA's and MTA's - theoratically.
However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a STA
by default. I can change this to MTA if I want to. But, what is the use of
this? Is it bad? Good? Can anyone give me a practicle example of when you
should use STA and when MTA?

Cheers,

Razzie

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

AFAIK win apps should be declared as STA this is required for some win
controls. so I would not change that.

take a look at this article :
http://blogs.msdn.com/cbrumme/archiv.../02/66219.aspx

it explain it a little bit more.

Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Razzie" <ra****@quicknet.nl> wrote in message
news:uh**************@TK2MSFTNGP15.phx.gbl...

Hey all,

I somewhat know of the differences between STA's and MTA's - theoratically. However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a STA by default. I can change this to MTA if I want to. But, what is the use of
this? Is it bad? Good? Can anyone give me a practicle example of when you
should use STA and when MTA?

Cheers,

Razzie

[Nicholas Paldino [.NET/C# MVP]]

Razzie,

Aside from what previous posters have mentioned, is there a reason that
you want to do this? What benefit are you seeking from doing this?
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Razzie" <ra****@quicknet.nl> wrote in message
news:uh**************@TK2MSFTNGP15.phx.gbl...

Hey all,

I somewhat know of the differences between STA's and MTA's -
theoratically. However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a
STA by default. I can change this to MTA if I want to. But, what is the
use of this? Is it bad? Good? Can anyone give me a practicle example of
when you should use STA and when MTA?

Cheers,

Razzie

[Stoitcho Goutsev \(100\) [C# MVP]]

Hi Razzie,

If you change the UI thread to be MTA you'll change it back very soon :)
You'll get an exception saying that STA is required by WindowsForms. That is
because WindowsForms uses COM. Chances not to get that exception are not
big.

--

Stoitcho Goutsev (100) [C# MVP]
"Razzie" <ra****@quicknet.nl> wrote in message
news:uh**************@TK2MSFTNGP15.phx.gbl...

Hey all,

I somewhat know of the differences between STA's and MTA's -
theoratically. However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a
STA by default. I can change this to MTA if I want to. But, what is the
use of this? Is it bad? Good? Can anyone give me a practicle example of
when you should use STA and when MTA?

Cheers,

Razzie

[Razzie]

I scanned that blog - it's why I asked this question actually :) It's good
theory, but it does not explain the practical use of it AFAICT.

Thanks.

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us> wrote
in message news:O2****************@TK2MSFTNGP12.phx.gbl...

Hi,

AFAIK win apps should be declared as STA this is required for some win
controls. so I would not change that.

take a look at this article :
http://blogs.msdn.com/cbrumme/archiv.../02/66219.aspx

it explain it a little bit more.

Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Razzie" <ra****@quicknet.nl> wrote in message
news:uh**************@TK2MSFTNGP15.phx.gbl...

Hey all,

I somewhat know of the differences between STA's and MTA's -

theoratically.

However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a

STA

by default. I can change this to MTA if I want to. But, what is the use
of
this? Is it bad? Good? Can anyone give me a practicle example of when you
should use STA and when MTA?

Cheers,

Razzie

[Razzie]

Hello Nicholas,

It is pure curiousity and from an eductational point of view, actually. I've
made multi-threaded applications, but never knew about the STA and MTA. So I
was wondering - when do you use STA, when MTA, what are the differences in
terms of performance.

Thanks,

Razzie

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.com> wrote in
message news:%2****************@TK2MSFTNGP14.phx.gbl...

Razzie,

Aside from what previous posters have mentioned, is there a reason that
you want to do this? What benefit are you seeking from doing this?
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Razzie" <ra****@quicknet.nl> wrote in message
news:uh**************@TK2MSFTNGP15.phx.gbl...

Hey all,

I somewhat know of the differences between STA's and MTA's -
theoratically. However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a
STA by default. I can change this to MTA if I want to. But, what is the
use of this? Is it bad? Good? Can anyone give me a practicle example of
when you should use STA and when MTA?

Cheers,

Razzie

[Scott Allen]

Hi Razzie:

You can make your application multi-threaded without changing the
apartment state.

In general, the only time you want to explicitly set the apartment
state is if you are doing COM interop with STA components. You want
your thread apartment type to match the threading model of any COM
objects the thread uses to minimize performance hits. As other posters
pointed out, there are additional reasons for setting the STA state
for Main.

--
Scott
http://www.OdeToCode.com/blogs/scott/

On Tue, 26 Oct 2004 16:06:43 +0200, "Razzie" <ra****@quicknet.nl>
wrote:

Hello Nicholas,

It is pure curiousity and from an eductational point of view, actually. I've
made multi-threaded applications, but never knew about the STA and MTA. So I
was wondering - when do you use STA, when MTA, what are the differences in
terms of performance.

Thanks,

Razzie

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.com> wrote in
message news:%2****************@TK2MSFTNGP14.phx.gbl...

Razzie,

Aside from what previous posters have mentioned, is there a reason that
you want to do this? What benefit are you seeking from doing this?
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Razzie" <ra****@quicknet.nl> wrote in message
news:uh**************@TK2MSFTNGP15.phx.gbl...

Hey all,

I somewhat know of the differences between STA's and MTA's -
theoratically. However, when it comes to practical use of this, I don't.

When I create a simple WinForms application, the main process runs in a
STA by default. I can change this to MTA if I want to. But, what is the
use of this? Is it bad? Good? Can anyone give me a practicle example of
when you should use STA and when MTA?

Cheers,

Razzie