Scheduled VB.NEt program

[LittleRob]

I'm having problems using Windows Task scheduler (or AT or SCHTASKS) to
run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.showdi alog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad event
doesn't. I then get a System.InvalidO perationExcepti on in the Eventlog
for that machine.

Why is this so hard, when VB6 can do this no problem?

Thanks

Rob

[Patrice]

On which statements does it fail ?

IMO it is caused more likely by the execution context rather than by some
VB6 vs VB.NET issue. For example an application that would try to use the
printer under a service account could fail as in this case the user profile
is not loaded and sop there are no default printers available...
"LittleRob" <gr************ *@greymouse.co. uka écrit dans le message de
news: 5r************* @mid.individual .net...

I'm having problems using Windows Task scheduler (or AT or SCHTASKS) to
run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.showdi alog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad event
doesn't. I then get a System.InvalidO perationExcepti on in the Eventlog for
that machine.

Why is this so hard, when VB6 can do this no problem?

Thanks

Rob

[LittleRob]

Patrice wrote:

On which statements does it fail ?

IMO it is caused more likely by the execution context rather than by some
VB6 vs VB.NET issue. For example an application that would try to use the
printer under a service account could fail as in this case the user profile
is not loaded and sop there are no default printers available...
"LittleRob" <gr************ *@greymouse.co. uka écrit dans le message de
news: 5r************* @mid.individual .net...

>I'm having problems using Windows Task scheduler (or AT or SCHTASKS) to
run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.showd ialog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad event
doesn't. I then get a System.InvalidO perationExcepti on in the Eventlog for
that machine.

Why is this so hard, when VB6 can do this no problem?

Thanks

Rob

Patrice

Thanks for the reply, but it doesn't fail on any of my code.

I added some logging:

1. Logging in the Sub Main() is OK

2. Logging in the form's New() is OK

3. Logging in the FormLoad event never gets executed.

It seems to me that I just can't show a form (using .ShowDialog) if the
code is to run from a scheduler, but I can't be the only person out
there with this problem. Well actually I know I'm not as I do get some
hits when I Google, but only a few, and never with a workaround.

Thanks

Rob

[Armin Zingler]

"LittleRob" <gr************ *@greymouse.co. ukschrieb

I'm having problems using Windows Task scheduler (or AT or SCHTASKS)
to run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.showdi alog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad
event doesn't. I then get a System.InvalidO perationExcepti on in the
Eventlog for that machine.

Why is this so hard, when VB6 can do this no problem?

I tried it and it works without an error. Are you logged-in when the task
starts? If you are not, it is not possible. You'd have to write a service
w/o a UI.
Armin

[Phill W.]

LittleRob wrote:

I'm having problems using Windows Task scheduler (or AT or SCHTASKS) to
run a VB.NET program unattended.

Sub Main()
MainForm.showdi alog
End Sub

Using ShowDialog on your /main/ form is a Bad Idea. Use ...

Application.Run ( New MainForm )

.... instead.

Without this, your form has no Windows Message loop to run in and so it
ends just as soon as it starts (which is probably why the Form's
constructor (sub New) is getting called but the Form is never loaded or
shown.

Also, if your application is running "unattended ", why is it showing a
Form (that no-one will be able to see or interact with)?

The Task Scheduler is a Windows Service which, generally speaking,
cannot display anything on screen. Indeed, showing a /dialog/
(typically a MsgBox) from a service /usually/ gets intercepted by
Windows and written to the Event Log instead!

HTH,
Phill W.

[Patrice]

And what are the task parameters ? Do you have an open session when this
tasks runs ? Under which account does it run ?

Basially the idea is that if you don't have any active desktop then the
application can't show a form... I'm not sure if a scheduled tasks with a ui
should be shown in the current user desktop if one is available ? You could
try using notepad for example to see how it reacts...

If you want to run a UI without any desktop this is just not possible. You
may want to explain what is the exact purpose of this application...

--
Patrice

"LittleRob" <gr************ *@greymouse.co. uka écrit dans le message de
news: 5r************* @mid.individual .net...

Patrice wrote:

>On which statements does it fail ?

IMO it is caused more likely by the execution context rather than by some
VB6 vs VB.NET issue. For example an application that would try to use the
printer under a service account could fail as in this case the user
profile is not loaded and sop there are no default printers available...
"LittleRob" <gr************ *@greymouse.co. uka écrit dans le message de
news: 5r************* @mid.individual .net...

>>I'm having problems using Windows Task scheduler (or AT or SCHTASKS) to
run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.show dialog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad event
doesn't. I then get a System.InvalidO perationExcepti on in the Eventlog
for that machine.

Why is this so hard, when VB6 can do this no problem?

Thanks

Rob

Patrice

Thanks for the reply, but it doesn't fail on any of my code.

I added some logging:

1. Logging in the Sub Main() is OK

2. Logging in the form's New() is OK

3. Logging in the FormLoad event never gets executed.

It seems to me that I just can't show a form (using .ShowDialog) if the
code is to run from a scheduler, but I can't be the only person out there
with this problem. Well actually I know I'm not as I do get some hits when
I Google, but only a few, and never with a workaround.

Thanks

Rob

[LittleRob]

Patrice wrote:

And what are the task parameters ? Do you have an open session when this
tasks runs ? Under which account does it run ?

Basially the idea is that if you don't have any active desktop then the
application can't show a form... I'm not sure if a scheduled tasks with a ui
should be shown in the current user desktop if one is available ? You could
try using notepad for example to see how it reacts...

If you want to run a UI without any desktop this is just not possible. You
may want to explain what is the exact purpose of this application...

--
Patrice

"LittleRob" <gr************ *@greymouse.co. uka écrit dans le message de
news: 5r************* @mid.individual .net...

>Patrice wrote:

>>On which statements does it fail ?

IMO it is caused more likely by the execution context rather than by some
VB6 vs VB.NET issue. For example an application that would try to use the
printer under a service account could fail as in this case the user
profile is not loaded and sop there are no default printers available...
"LittleRob" <gr************ *@greymouse.co. uka écrit dans le message de
news: 5r************* @mid.individual .net...
I'm having problems using Windows Task scheduler (or AT or SCHTASKS) to
run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.sho wdialog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad event
doesn't. I then get a System.InvalidO perationExcepti on in the Eventlog
for that machine.

Why is this so hard, when VB6 can do this no problem?

Thanks

Rob

Patrice

Thanks for the reply, but it doesn't fail on any of my code.

I added some logging:

1. Logging in the Sub Main() is OK

2. Logging in the form's New() is OK

3. Logging in the FormLoad event never gets executed.

It seems to me that I just can't show a form (using .ShowDialog) if the
code is to run from a scheduler, but I can't be the only person out there
with this problem. Well actually I know I'm not as I do get some hits when
I Google, but only a few, and never with a workaround.

Thanks

Rob

Patrice (and everyone else)

Thanks for your reply.

I understand that showing a form during an unattended session seems a
little odd, but my point is that I want to be able to run the same code
whether logged in or not. If I run my program interactively then I see a
progressbar and some IO. If I'm not logged in then that goes off into
the aether, but the program should still run.

I have re-written the code to run differently when I pass it a
commandline parameter its just a shame I need to do this.

The other issue is that VB6 could do this with no problems. So it seems
a backwards step that I have to code around this.

Rob

[LittleRob]

Armin Zingler wrote:

"LittleRob" <gr************ *@greymouse.co. ukschrieb

>I'm having problems using Windows Task scheduler (or AT or SCHTASKS)
to run a VB.NET program unattended.

I'm able to reduce it to some really simple code that still fails

My program has a Sub Main something like

Sub Main()

MainForm.showd ialog

End Sub

In MainForm the New() does execute, but code in the MainFormLoad
event doesn't. I then get a System.InvalidO perationExcepti on in the
Eventlog for that machine.

Why is this so hard, when VB6 can do this no problem?

I tried it and it works without an error. Are you logged-in when the task
starts? If you are not, it is not possible. You'd have to write a
service w/o a UI.
Armin

Armin

No I'm not logged in when it runs. I'm not even in the same postcode, if
you see my reply to Patrice you'll see why I'm a bit confused, and
disappointed in VB.NET

Thanks

Rob

[LittleRob]

Phill W. wrote:

LittleRob wrote:

>I'm having problems using Windows Task scheduler (or AT or SCHTASKS)
to run a VB.NET program unattended.

> Sub Main()
MainForm.showdi alog
End Sub

Using ShowDialog on your /main/ form is a Bad Idea. Use ...

Application.Run ( New MainForm )

... instead.

Without this, your form has no Windows Message loop to run in and so it
ends just as soon as it starts (which is probably why the Form's
constructor (sub New) is getting called but the Form is never loaded or
shown.

Also, if your application is running "unattended ", why is it showing a
Form (that no-one will be able to see or interact with)?

The Task Scheduler is a Windows Service which, generally speaking,
cannot display anything on screen. Indeed, showing a /dialog/
(typically a MsgBox) from a service /usually/ gets intercepted by
Windows and written to the Event Log instead!

HTH,
Phill W.

Phil

Thanks for taking the time to reply. If you see my reply to Patrice
you'll see what I'm trying to achieve. It seems odd that this was so
easy in VB6 and so hard in VB.NET

Thanks

Rob

[LittleRob]

Armin Zingler wrote:

>

>If I run my program interactively
then I see a progressbar and some IO. If I'm not logged in then that
goes off into the aether, but the program should still run.

I have re-written the code to run differently when I pass it a
commandline parameter its just a shame I need to do this.

No, it's a good solution.

Armin

I totally disagree with you. Having 2 pathways through the code and
needing 2 shortcuts installed on site is a recipe for disaster. What
would have been a good solution is the VB6 way of doing things.

So what if I display a form that nobody sees. It might look odd, but
does it matter?

Already today I ran interactively using the wrong method and of course I
sat there waiting for something to happen, which it was - invisibly.

I wonder if there is a way to tell in code what is going on.

Rob