What thread does Timer operate on

The answer is: "It depends." There are several timers available.

System.Windows.Forms.Timer (from the Components section of the Toolbox)
executes in the STAThread of the UI.

System.Timers.Timer creates a separate thread, as does Sytem.Threading.Timer
(these are not exactly equivalent to each other).

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.

On 14 Ago, 17:52, "Dick Grier" <dick_grierNOSPAM@.msn.comwrote:

The answer is: *"It depends." *There are several timers available.

System.Windows.Forms.Timer (from the Components section of the Toolbox)
executes in the STAThread of the UI.

System.Timers.Timer creates a separate thread, as does Sytem.Threading.Timer
(these are not exactly equivalent to each other).

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
Seewww.hardandsoftware.netfor details and contact information.

Dear Dick,

I am new to this topic and interested.
I think that I have done some experiment by creating
System.Windows.Forms.Timer
within a thread and it worked fine.

Perhaps you are referring to the situation where one drags the
component on a form ?

Could you explain it better? I have the impression that there no need
to have a UI
to have the System.Windows.Forms.Timer work ... Is that right ? Nor it
necessarily
run on the UI thread...(?) Perhaps I am missing something ...
-P

On 2008-08-14, pamela fluente <pa***********@libero.itwrote:

On 14 Ago, 17:52, "Dick Grier" <dick_grierNOSPAM@.msn.comwrote:

>The answer is: *"It depends." *There are several timers available.

System.Windows.Forms.Timer (from the Components section of the Toolbox)
executes in the STAThread of the UI.

System.Timers.Timer creates a separate thread, as does Sytem.Threading.Timer
(these are not exactly equivalent to each other).

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
Seewww.hardandsoftware.netfor details and contact information.

Dear Dick,

I am new to this topic and interested.
I think that I have done some experiment by creating
System.Windows.Forms.Timer
within a thread and it worked fine.

Perhaps you are referring to the situation where one drags the
component on a form ?

Could you explain it better? I have the impression that there no need
to have a UI
to have the System.Windows.Forms.Timer work ... Is that right ? Nor it
necessarily
run on the UI thread...(?) Perhaps I am missing something ...
-P

You are... The System.Windows.Forms.Timer requires a message pump on the
thread it is on to work. It is really a wrapper dealing with WM_TIMER
notification's. If you search, you will find that this is a common mistake
that people make when writing windows services - they will use a
System.Windows.Forms.Timer and then wonder why it never fires :)

--
Tom Shelton

On 14 Ago, 19:23, Tom Shelton <tom_shel...@comcastXXXXXXX.netwrote:

On 2008-08-14, pamela fluente <pamelaflue...@libero.itwrote:

On 14 Ago, 17:52, "Dick Grier" <dick_grierNOSPAM@.msn.comwrote:

The answer is: *"It depends." *There are several timers available.

System.Windows.Forms.Timer (from the Components section of the Toolbox)
executes in the STAThread of the UI.

System.Timers.Timer creates a separate thread, as does Sytem.Threading..Timer
(these are not exactly equivalent to each other).

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
Seewww.hardandsoftware.netfordetails and contact information.

Dear Dick,

*I am new to this topic and interested.
*I think that I have done some experiment by creating
System.Windows.Forms.Timer
*within a thread and it worked fine.

*Perhaps you are referring to the situation where one drags the
component on a form ?

Could you explain it better? I have the impression that there no need
to have a UI
to have the System.Windows.Forms.Timer work ... Is that right ? Nor it
necessarily
run on the UI thread...(?) * Perhaps I am missing something ...

-P

You are... *The System.Windows.Forms.Timer requires a message pump on the
thread it is on to work. *It is really a wrapper dealing with WM_TIMER
notification's. *If you search, you will find that this is a common mistake
that people make when writing windows services - they will use a
System.Windows.Forms.Timer and then wonder why it never fires :)

--
Tom Shelton- Nascondi testo citato

- Mostra testo citato -

hmm This is good to know. So I can create it but it will not work!
Very useful. Thanks a lot for pointing that out.

It's still rather misterious to me why a normal timer will not work
and
not sure why that "message pump" is needed... but I guess I will find
out
with practice ... :-)

-P

While it is possible for the forms Timer to work without a form, a message
pump is required... So, it isn't practical for you to attempt to use this
timer in an application that has no UI (IMO). The additional code needed is
too much to make it worthwhile.

This is one (of the) reason(s) that the System.Timers.Timer object is
available.

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.

On 15 Ago, 18:41, "Dick Grier" <dick_grierNOSPAM@.msn.comwrote:

While it is possible for the forms Timer to work without a form, a message
pump is required... So, it isn't practical for you to attempt to use this
timer in an application that has no UI (IMO). *The additional code needed is
too much to make it worthwhile.

This is one (of the) reason(s) that the System.Timers.Timer object is
available.

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
Seewww.hardandsoftware.netfor details and contact information.

Thank you. I have studied now the timers class and I think I am going
to replace most of my times with this one.

One thing that is *now* misterious to me is that, while I did not
realize the working of the "form" timer, is that
I do have a few timer defined several istances of a class that is not
attached to a GUI. And it does fire and works perfectly fine.

I am really puzzled about this and now I do not understand how is it
possible that those timers are working (?)

By some magic, looks like that .NET is able to "reconnect" those
timers to some form of the application. But I have no idea how this is
possible !?
Any idea?

-P

On 2008-08-15, pamela fluente <pa***********@libero.itwrote:

On 15 Ago, 18:41, "Dick Grier" <dick_grierNOSPAM@.msn.comwrote:

>While it is possible for the forms Timer to work without a form, a message
pump is required... So, it isn't practical for you to attempt to use this
timer in an application that has no UI (IMO). *The additional code needed is
too much to make it worthwhile.

This is one (of the) reason(s) that the System.Timers.Timer object is
available.

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
Seewww.hardandsoftware.netfor details and contact information.

Thank you. I have studied now the timers class and I think I am going
to replace most of my times with this one.

One thing that is *now* misterious to me is that, while I did not
realize the working of the "form" timer, is that
I do have a few timer defined several istances of a class that is not
attached to a GUI. And it does fire and works perfectly fine.

I am really puzzled about this and now I do not understand how is it
possible that those timers are working (?)

By some magic, looks like that .NET is able to "reconnect" those
timers to some form of the application. But I have no idea how this is
possible !?
Any idea?

-P

They will work if:

1) they are in a windows forms application
2) the instances of the class containing them is created on the same thread as
the form that instantiated them...

They will work because there is a message pump on the thread that created
them.

--
Tom Shelton

On 15 Ago, 23:39, Tom Shelton <tom_shel...@comcastXXXXXXX.netwrote:

On 2008-08-15, pamela fluente <pamelaflue...@libero.itwrote:

On 15 Ago, 18:41, "Dick Grier" <dick_grierNOSPAM@.msn.comwrote:

While it is possible for the forms Timer to work without a form, a message
pump is required... So, it isn't practical for you to attempt to use this
timer in an application that has no UI (IMO). *The additional code needed is
too much to make it worthwhile.

This is one (of the) reason(s) that the System.Timers.Timer object is
available.

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
Seewww.hardandsoftware.netfordetails and contact information.

Thank you. I have studied now the timers class and I think I am going
to replace most of my times with this one.

One thing that is *now* misterious to me is that, while I did not
realize the working of the "form" timer, is that
I do have a few timer defined several istances of a class that is not
attached to a GUI. And it does fire and works perfectly fine.

I am really puzzled about this and now I do not understand how is it
possible that those timers are working (?)

By some magic, looks like that .NET is able to "reconnect" those
timers to some form of the application. But I have no idea how this is
possible !?
Any idea?

-P

They will work if:

1) they are in a windows forms application
2) the instances of the class containing them is created on the same thread as
the form that instantiated them...

They will work because there is a message pump on the thread that created
them.

--
Tom Shelton- Nascondi testo citato

- Mostra testo citato -

Thanks Tom. Very helpful.

-P