Threading and Scope

[tomb]

Hi all.
I can't find anything to explain how to prevent losing my object reference.

I have a function that instantiates a document object, passes it to
another class, then uses a thread for the other class to process data
and populate the document with a report, then open the document. It all
works great except the document opens and immediately closes.

What I don't understand is this:
If I Dim as New the document object in a function, then process the data
and report in the other class without threading, the document opens and
stays open even though the function is exited and the document object
and other class go out of scope.
But, if I do the same thing using threading, the document and class
still go out of scope, but now I lose the document completely.

Can anyone explain this? Better yet, how to avoid this? Or point me to
a reference?

So frustrating, so frustrating...

Thanks,
Tom

[Samuel Shulman]

Re: Threading and Scope

It Word document?


"tomb" <tomb@technetce nter.comwrote in message
news:0Zqtg.2233 0$Ud4.14111@big news1.bellsouth .net...

Hi all.
I can't find anything to explain how to prevent losing my object
reference.
>
I have a function that instantiates a document object, passes it to
another class, then uses a thread for the other class to process data and
populate the document with a report, then open the document. It all works
great except the document opens and immediately closes.
What I don't understand is this:
If I Dim as New the document object in a function, then process the data
and report in the other class without threading, the document opens and
stays open even though the function is exited and the document object and
other class go out of scope.
But, if I do the same thing using threading, the document and class still
go out of scope, but now I lose the document completely.
>
Can anyone explain this? Better yet, how to avoid this? Or point me to a
reference?
>
So frustrating, so frustrating...
>
Thanks,
Tom

[tomb]

Re: Threading and Scope

It's a generic document form with vb.net.

T

Samuel Shulman wrote:

>It Word document?
>
>
>"tomb" <tomb@technetce nter.comwrote in message
>news:0Zqtg.223 30$Ud4.14111@bi gnews1.bellsout h.net...
>
>

>>Hi all.
>>I can't find anything to explain how to prevent losing my object
>>reference.
>>
>>I have a function that instantiates a document object, passes it to
>>another class, then uses a thread for the other class to process data and
>>populate the document with a report, then open the document. It all works
>>great except the document opens and immediately closes.
>>What I don't understand is this:
>>If I Dim as New the document object in a function, then process the data
>>and report in the other class without threading, the document opens and
>>stays open even though the function is exited and the document object and
>>other class go out of scope.
>>But, if I do the same thing using threading, the document and class still
>>go out of scope, but now I lose the document completely.
>>
>>Can anyone explain this? Better yet, how to avoid this? Or point me to a
>>reference?
>>
>>So frustrating, so frustrating...
>>
>>Thanks,
>>Tom
>>
>>

>
>
>
>

[Branco Medeiros]

Re: Threading and Scope


tomb wrote:
<snip>

I have a function that instantiates a document object, passes it to
another class, then uses a thread for the other class to process data
and populate the document with a report, then open the document. It all
works great except the document opens and immediately closes.

<snip>

Since the form is created in another thread, as soon as the threaded
function finishes, the thread vanishes and the form 'dies'.

One possible solution would be to open the form with ShowDialog(), but
notice that this will show the form modally and may prevent your
function from working.

HTH,

Branco

[tomb]

Re: Threading and Scope

Actually, the form is declared and instantiated in my non-threaded
function, then passed to the other class, that then is called in a
thread to do the processing. But I appreciate the attempt.

T

Branco Medeiros wrote:

>tomb wrote:
><snip>
>
>

>>I have a function that instantiates a document object, passes it to
>>another class, then uses a thread for the other class to process data
>>and populate the document with a report, then open the document. It all
>>works great except the document opens and immediately closes.
>>
>>

><snip>
>
>Since the form is created in another thread, as soon as the threaded
>function finishes, the thread vanishes and the form 'dies'.
>
>One possible solution would be to open the form with ShowDialog(), but
>notice that this will show the form modally and may prevent your
>function from working.
>
>HTH,
>
>Branco
>
>
>

[Branco Medeiros]

Re: Threading and Scope


tomb wrote:

Actually, the form is declared and instantiated in my non-threaded
function, then passed to the other class, that then is called in a
thread to do the processing. But I appreciate the attempt.

It would help if you posted some code, then... =)

Regards,

Branco.

[Michael D. Ober]

Re: Threading and Scope

You need to pass a reference to your document to your thread. Otherwise,
when the function that opens the document terminates, your document goes out
of scope and the GC reclaims it.

Mike Ober.

"tomb" <tomb@technetce nter.comwrote in message
news:0Zqtg.2233 0$Ud4.14111@big news1.bellsouth .net...

Hi all.
I can't find anything to explain how to prevent losing my object

reference.

>
I have a function that instantiates a document object, passes it to
another class, then uses a thread for the other class to process data
and populate the document with a report, then open the document. It all
works great except the document opens and immediately closes.
>
What I don't understand is this:
If I Dim as New the document object in a function, then process the data
and report in the other class without threading, the document opens and
stays open even though the function is exited and the document object
and other class go out of scope.
But, if I do the same thing using threading, the document and class
still go out of scope, but now I lose the document completely.
>
Can anyone explain this? Better yet, how to avoid this? Or point me to
a reference?
>
So frustrating, so frustrating...
>
Thanks,
Tom
>