Hi,
Does Form.ShowDialog () start new thread ?
If yes how is solved cross-thread operations?
Thx
Does Form.ShowDialog () start new thread ?
If yes how is solved cross-thread operations?
Thx
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Re: does ShowDialog start new thread ?
shark wrote:No, it doesn't.Hi,
>
Does Form.ShowDialog () start new thread ?
If yes how is solved cross-thread operations?
>
Thx
--
Lasse Vågsæther Karlsen
mailto:lasse@vk arlsen.no
PGP KeyID: 0xBCDEA2E3
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Re: does ShowDialog start new thread ?
On May 5, 4:26 pm, Lasse Vågsæther Karlsen <la...@vkarlsen .nowrote:I was under a notion that Show and ShowDialog would executeon ashark wrote:>Hi,>Does Form.ShowDialog () start new thread ?
If yes how is solved cross-thread operations?>Thx
No, it doesn't.
>
--
Lasse Vågsæther Karlsen
mailto:la...@vk arlsen.nohttp://presentationmod e.blogspot.com/
PGP KeyID: 0xBCDEA2E3
different thread. Seems interesting..Th anks Lasse.
Comment
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Re: does ShowDialog start new thread ?
On 5月5æ—¥, 下åˆ7æ—¶29分 , "Aneesh Pulukkul [http://dotnet-
revolutions.blo gspot.com]" <anees...@gmail .comwrote:Every window should have a thread to process messages, right?On May 5, 4:26 pm, Lasse Vågsæther Karlsen <la...@vkarlsen .nowrote:
>>shark wrote:Hi,>Does Form.ShowDialog () start new thread ?
If yes how is solved cross-thread operations?>Thx>No, it doesn't.>--
Lasse Vågsæther Karlsen
mailto:la...@vk arlsen.nohttp://presentationmod e.blogspot.com/
PGP KeyID: 0xBCDEA2E3
I was under a notion that Show and ShowDialog would executeon a
different thread. Seems interesting..Th anks Lasse.
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Re: does ShowDialog start new thread ?
"Aneesh Pulukkul [http://dotnet-revolutions.blo gspot.com]"
<aneesh.p@gmail .comwrote:
Try putting code after ShowDialog. It won't run until that second windowI was under a notion that Show and ShowDialog would executeon a
different thread.
closes. If ShowDialog just launched another thread, the code after
ShowDialog would run immediately.
Eq.
Comment
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Re: does ShowDialog start new thread ?
Hmm, I think that this is not a proof, because each modal window have it's
own message queue and that's why code after ShowDialog will not execute.
"Paul E Collins" <find_my_real_a ddress@CL4.orgw rote in message
news:fpqdnUwdJJ FfkILVnZ2dnUVZ8 u6dnZ2d@bt.com. .."Aneesh Pulukkul [http://dotnet-revolutions.blo gspot.com]"
<aneesh.p@gmail .comwrote:
>>>I was under a notion that Show and ShowDialog would executeon a different
>thread.
Try putting code after ShowDialog. It won't run until that second window
closes. If ShowDialog just launched another thread, the code after
ShowDialog would run immediately.
>
Eq.
>
>Comment
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Re: does ShowDialog start new thread ?
shark wrote:This may not be a perfect test, but I just ran a simple form with a CancelButtonHi,
>
Does Form.ShowDialog () start new thread ?
If yes how is solved cross-thread operations?
setup using ShowDialog(), and had the threads window open in VS2005 (Debug ->
Windows -Threads) and no new threads appeared to spawn to handle the dialog.
There may be other reasons why that happened though.
Chris.
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Re: does ShowDialog start new thread ?
On Mon, 05 May 2008 05:19:41 -0700, Robin <zouyongbin@gma il.comwrote:
Wrong. A thread that owns one or more windows will have a single messageEvery window should have a thread to process messages, right?
pump loop that dispatches messages to _all_ windows owned by that thread.
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Re: does ShowDialog start new thread ?
On Mon, 05 May 2008 07:27:21 -0700, shark <mark@poczta.on et.plwrote:
Why do you think each modal window has its own message queue?Hmm, I think that this is not a proof, because each modal window have
it's own message queue and that's why code after ShowDialog will not
execute.
There's a single queue per thread, messages for all windows owned by that
thread are placed in the queue, and a given thread will have a single
message pump loop active at any given time. Your premise is false, so no
conclusion based on premise that could be useful.
As for why code after ShowDialog() doesn't execute until the window is
closed...
In the case of a modal window, the modal code that handles displaying the
window runs its own message pump loop and doesn't return until the window
is closed. That's why the code after ShowDialog() won't execute until the
window is closed.
But the message pump loop handling the modal window is running on the same
thread in which you called ShowDialog(), and will dispatch messages to
_all_ windows owned by that thread, not just the modal window that was
displayed.
Pete
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Re: does ShowDialog start new thread ?
So in our cases we have two windows: first is main form window and the
second in modal dialog.
Are they created in the same thread?
How many message pump do we have in this case (seems like 2)?
"Peter Duniho" <NpOeStPeAdM@nn owslpianmk.comw rote in message
news:op.uaoweib 78jd0ej@petes-computer.local. ..On Mon, 05 May 2008 05:19:41 -0700, Robin <zouyongbin@gma il.comwrote:
>>>Every window should have a thread to process messages, right?
Wrong. A thread that owns one or more windows will have a single message
pump loop that dispatches messages to _all_ windows owned by that thread.Comment
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Re: does ShowDialog start new thread ?
On Mon, 05 May 2008 23:04:11 -0700, shark <mark@poczta.on et.plwrote:
Impossible to answer without seeing the code. The windows are created inSo in our cases we have two windows: first is main form window and the
second in modal dialog.
>
Are they created in the same thread?
whatever thread executes the code that creates them. But by default,
without you introducing an additional thread to the picture, yes...the
modal dialog would be created on the same thread as any other window.
Why do you say "seems like 2"? Assuming the modal dialog is created inHow many message pump do we have in this case (seems like 2)?
the same thread as the main form window, then there will only be a single
message pump running at a given time. When the modal dialog is being
shown, the message pump that handles the modal nature of the dialog will
be pumping messages for _all_ windows that had been created on that thread.
If you create the modal dialog on a different thread, then you'll have two
message pumps: the main GUI thread's pump, and the one that's started when
you show the modal dialog. But so far you haven't given any reason for us
to believe that the modal dialog is created on a different thread.
If you have some specific code to show, it will be possible to tell you
whether more than one thread is involved. Otherwise, it won't be possible
to say for sure. But generally speaking, if you are showing a modal
dialog in response to some event raised by an existing Control instance
(including, for example, a form), without delegating that work to some
other thread, the modal dialog will be created on the same thread in which
that existing Control instance was created.
Pete
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Re: does ShowDialog start new thread ?
I had a problem similar to this, and I am still looking for the
solution.
I have an MDI form, instantiating a child form, calling the ShowDialog
method.
I works fine. Ithe problem is when the form is embbeded on a second
assembly, when it happens, it realy seems to start another thead,
becouse it don´t wait the window to close to continue the next step of
the procedure.
any idea?
Thanks and regards,
André Luiz Sobreiro
*** Sent via Developersdex http://www.developersdex.com ***
Comment
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Re: does ShowDialog start new thread ?
ShowDialog pauses the calling thread execution until the form has closed,
Show does not. ShowDialog would not be able to return the proper dialog
result if the thread continued processing. I don't see how putting the class
in another assembly would make any difference at all.
Perhaps you have a background thread that is closing the form on you.
"André Luiz Sobreiro" <sobreiro@yahoo .comwrote in message
news:OLfQHZV1IH A.5300@TK2MSFTN GP06.phx.gbl...>
>
I had a problem similar to this, and I am still looking for the
solution.
>
I have an MDI form, instantiating a child form, calling the ShowDialog
method.
>
I works fine. Ithe problem is when the form is embbeded on a second
assembly, when it happens, it realy seems to start another thead,
becouse it don´t wait the window to close to continue the next step of
the procedure.
>
any idea?
>
Thanks and regards,
André Luiz Sobreiro
>
*** Sent via Developersdex http://www.developersdex.com ***Comment
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Re: does ShowDialog start new thread ?
On Mon, 23 Jun 2008 18:07:07 -0700, Jeff Winn <jwinn@nospam.c omwrote:
Important nit: ShowDialog() does not literally "pause the callingShowDialog pauses the calling thread execution until the form has
closed, Show does not. ShowDialog would not be able to return the proper
dialog result if the thread continued processing. I don't see how
putting the class in another assembly would make any difference at all.
thread". It's true that the method call ShowDialog() doesn't return until
the form is closed. But the thread itself continues to execute. It
simply spends its time in message pump loop handling the dialog, rather
than the top-level message pump loop initiated at the beginning of the
thread.
As for the previous poster's question: it's not impossible that you might
have some code that creates a new thread in which a dialog is shown.
However, without a concise-but-complete code sample that reliably
demonstrates your problem, it's not likely your question will be
answered. It's too vague as-is.
Pete
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Re: does ShowDialog start new thread ?
Ah, guess I should have been a bit clearer on what I was thinking.
Thanks Pete
"Peter Duniho" <NpOeStPeAdM@nn owslpianmk.comw rote in message
news:op.uc9aqnz w8jd0ej@petes-computer.local. ..On Mon, 23 Jun 2008 18:07:07 -0700, Jeff Winn <jwinn@nospam.c omwrote:
>>>ShowDialog pauses the calling thread execution until the form has
>closed, Show does not. ShowDialog would not be able to return the proper
>dialog result if the thread continued processing. I don't see how
>putting the class in another assembly would make any difference at all.
Important nit: ShowDialog() does not literally "pause the calling
thread". It's true that the method call ShowDialog() doesn't return until
the form is closed. But the thread itself continues to execute. It
simply spends its time in message pump loop handling the dialog, rather
than the top-level message pump loop initiated at the beginning of the
thread.
>
As for the previous poster's question: it's not impossible that you might
have some code that creates a new thread in which a dialog is shown.
However, without a concise-but-complete code sample that reliably
demonstrates your problem, it's not likely your question will be
answered. It's too vague as-is.
>
PeteComment
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