Stop a function

[Ricardo]

I made a program that generate random numbers and put it in a listbox when
the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???
[]s...

[William Ryan eMVP]

There are a few ways, but you could use IAsyncResult for instance, and use a
while loop. the while could read in a bool. When the user hits the button,
set the bool to false. By using another thread, you won't freeze up the UI.
http://www.knowdotnet.com/articles/delegates.html
"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...

I made a program that generate random numbers and put it in a listbox when
the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???
[]s...

[cody]

> I made a program that generate random numbers and put it in a listbox when

the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???

You need to run that method in a separate Thread. If you press the button,
set a flag which you test in the method and return in this case.

--
cody

Freeware Tools, Games and Humour
http://www.deutronium.de.vu || http://www.deutronium.tk

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

Hi Ricardo,

There are a few ways of doing it , it all depend of how/where you run the
random generator, I will show you two escenarios
1- gen. runs on the same thread.

while you are generating numbers , between number generation you call
Application.DoE vents() this process the events queries, you can then use a
Stop button that set a flag to false, before the next number is generated yo
check for this flag, like this:

bool generate = true;
void generaterandom( object sender, EventArgs e )
{
while ( generate)
{
// generate it and update the UI
Application.DoE vents();
}

}
void Stop_OnClick( object sender, EventArgs e )
{
generate = false;
}

2- run the generator on another thread and then the Stop button can pause
the thread execution, remember that if you use this approach you have to
make sure that the call to update the interface be called in the main thread
using Control.Invoke

Pd: I will not post code for this as its a little more complex, just drop
me a note if you need it

HTH,

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

"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...

I made a program that generate random numbers and put it in a listbox when
the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???
[]s...

[Brad Williams]

Scenario #1 is preferable to spawning a thread, which would be difficult to
manage, test, debug, etc.

Brad Williams
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:u7******** ******@tk2msftn gp13.phx.gbl...

Hi Ricardo,

There are a few ways of doing it , it all depend of how/where you run the
random generator, I will show you two escenarios
1- gen. runs on the same thread.

while you are generating numbers , between number generation you call
Application.DoE vents() this process the events queries, you can then use a
Stop button that set a flag to false, before the next number is generated yo check for this flag, like this:

bool generate = true;
void generaterandom( object sender, EventArgs e )
{
while ( generate)
{
// generate it and update the UI
Application.DoE vents();
}

}
void Stop_OnClick( object sender, EventArgs e )
{
generate = false;
}

2- run the generator on another thread and then the Stop button can pause
the thread execution, remember that if you use this approach you have to
make sure that the call to update the interface be called in the main thread using Control.Invoke

Pd: I will not post code for this as its a little more complex, just drop
me a note if you need it

HTH,

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

"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...

I made a program that generate random numbers and put it in a listbox when the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???
[]s...

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

Hi,

It's as long as the operation to be performed is not lengthy, if it's the
UI will hang until the call to DoEvents() .
Cheers,

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

"Brad Williams" <sp**@spam.co m> wrote in message
news:c7******** **@news01.intel .com...

Scenario #1 is preferable to spawning a thread, which would be difficult to manage, test, debug, etc.

Brad Williams
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote in message news:u7******** ******@tk2msftn gp13.phx.gbl...

Hi Ricardo,

There are a few ways of doing it , it all depend of how/where you run the

random generator, I will show you two escenarios
1- gen. runs on the same thread.

while you are generating numbers , between number generation you call
Application.DoE vents() this process the events queries, you can then use a Stop button that set a flag to false, before the next number is generated

yo

check for this flag, like this:

bool generate = true;
void generaterandom( object sender, EventArgs e )
{
while ( generate)
{
// generate it and update the UI
Application.DoE vents();
}

}
void Stop_OnClick( object sender, EventArgs e )
{
generate = false;
}

2- run the generator on another thread and then the Stop button can

pause the thread execution, remember that if you use this approach you have to
make sure that the call to update the interface be called in the main

thread

using Control.Invoke

Pd: I will not post code for this as its a little more complex, just drop me a note if you need it

HTH,

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

"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...

I made a program that generate random numbers and put it in a listbox

when the user click go.
The problem is: how can i made a button stop, to stop the method that is running???
[]s...

[Iceman]

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > a
écrit dans le message de news:u7******** ******@tk2msftn gp13.phx.gbl...

Hi Ricardo,

There are a few ways of doing it , it all depend of how/where you run the
random generator, I will show you two escenarios
1- gen. runs on the same thread.

while you are generating numbers , between number generation you call
Application.DoE vents() this process the events queries, you can then use a
Stop button that set a flag to false, before the next number is generated yo check for this flag, like this:

bool generate = true;
void generaterandom( object sender, EventArgs e )
{
while ( generate)
{
// generate it and update the UI
Application.DoE vents();
}

}
void Stop_OnClick( object sender, EventArgs e )
{
generate = false;
}

2- run the generator on another thread and then the Stop button can pause
the thread execution, remember that if you use this approach you have to
make sure that the call to update the interface be called in the main thread using Control.Invoke

Pd: I will not post code for this as its a little more complex, just drop
me a note if you need it

HTH,

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

"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...

I made a program that generate random numbers and put it in a listbox when the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???
[]s...

Hi.

The use of DoEvent is a very risky practice. Indeed, any event can occur
during the call of doevent. It might change some input you are dealing with
in your generateRandom method.
You must be very cautious of not encounter some incoherences.
Althought it may look a little bit more complex, you should definitely use a
worker thread. It is much easier to control.

Fred

[Brad Williams]

"Iceman" <fr************ ************@ne uf.fr> wrote in message
news:c7******** **@aphrodite.gr ec.isp.9tel.net ...

The use of DoEvent is a very risky practice.

This is exactly how we handled this in Windows 3.1, and the code was ugly
but actually much less error prone than trying to herd threads.
Multithreaded programming is harder than most people realize, unfortunately.

Brad Williams

[Ricardo]

could you send the code of scenario 2 to my e-mail:
dr*******@terra .com.br

bye...
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:u7******** ******@tk2msftn gp13.phx.gbl...

Hi Ricardo,

There are a few ways of doing it , it all depend of how/where you run the
random generator, I will show you two escenarios
1- gen. runs on the same thread.

while you are generating numbers , between number generation you call
Application.DoE vents() this process the events queries, you can then use a
Stop button that set a flag to false, before the next number is generated yo check for this flag, like this:

bool generate = true;
void generaterandom( object sender, EventArgs e )
{
while ( generate)
{
// generate it and update the UI
Application.DoE vents();
}

}
void Stop_OnClick( object sender, EventArgs e )
{
generate = false;
}

2- run the generator on another thread and then the Stop button can pause
the thread execution, remember that if you use this approach you have to
make sure that the call to update the interface be called in the main thread using Control.Invoke

Pd: I will not post code for this as its a little more complex, just drop
me a note if you need it

HTH,

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

"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...

I made a program that generate random numbers and put it in a listbox when the user click go.
The problem is: how can i made a button stop, to stop the method that is
running???
[]s...

[Ricardo]

The UI is hanging, the scenario 1 not work...

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:eM******** ******@TK2MSFTN GP10.phx.gbl...

Hi,

It's as long as the operation to be performed is not lengthy, if it's the
UI will hang until the call to DoEvents() .
Cheers,

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

"Brad Williams" <sp**@spam.co m> wrote in message
news:c7******** **@news01.intel .com...

Scenario #1 is preferable to spawning a thread, which would be difficult to

manage, test, debug, etc.

Brad Williams
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us >

wrote

in message news:u7******** ******@tk2msftn gp13.phx.gbl...

Hi Ricardo,

There are a few ways of doing it , it all depend of how/where you run the random generator, I will show you two escenarios
1- gen. runs on the same thread.

while you are generating numbers , between number generation you call
Application.DoE vents() this process the events queries, you can then use a

Stop button that set a flag to false, before the next number is generated

yo

check for this flag, like this:

bool generate = true;
void generaterandom( object sender, EventArgs e )
{
while ( generate)
{
// generate it and update the UI
Application.DoE vents();
}

}
void Stop_OnClick( object sender, EventArgs e )
{
generate = false;
}

2- run the generator on another thread and then the Stop button can pause the thread execution, remember that if you use this approach you have

to make sure that the call to update the interface be called in the main thread

using Control.Invoke

Pd: I will not post code for this as its a little more complex, just

drop me a note if you need it

HTH,

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

"Ricardo" <dr*******@terr a.com.br> wrote in message
news:O9******** ******@TK2MSFTN GP12.phx.gbl...
> I made a program that generate random numbers and put it in a

listbox when

> the user click go.
> The problem is: how can i made a button stop, to stop the method

that is > running???
>
>
> []s...
>
>