Using ADO.NET in windows service. I'm getting no events (e.g. RecordChangeComplete)

  • Thread starter Thread starter ML
  • Start date Start date
M

ML

Hello,

I have some small code that opens a connection to an oledb-provider and
opens a recordset. Then creates a delegate to a RecordChangeComplete event
on the recordset.
When I put this code in a service (have tried both OnStart and in a separate
thread) I never get any RecordChangeComplete events. Although using the
exact same code in a form application the event works fine.
In both cases I can see that the oledb-provider is sending the right events,
but it seems they are trapped by the service somehow.

I have used the provider in services (written in C++) before, but never
using ADO / ADO.NET and it has always worked fine.

So what is ADO doing that behaves differently in a service-application than
in a Forms-application?

The code in the service looks like this:

protected override void OnStart(string[] args)
{
m_cn = new Connection();
m_rs = new Recordset();
m_cn.Open(Providerstring, "", "", 0);
m_rs.Open(Tablestring, m_cn, CursorTypeEnum.adOpenDynamic,
LockTypeEnum.adLockReadOnly, 0);
ADODB.RecordsetEvents_RecordChangeCompleteEventHandler delRecordComplete
= new
RecordsetEvents_RecordChangeCompleteEventHandler(RecordChangeComplete);
m_rs.RecordChangeComplete += delRecordComplete;
}

/Morgan L
 
Try this trick

http://dotnetjunkies.com/WebLog/sahilmalik/archive/2004/12/06/35295.aspx

To help you diagnose/debug your windows service like a windows app. Check
and see if the delegate is null for any crazy reason.

Also, by doing the above, and running it in debugmode, you are essentially
then running a windows application/not a service - that way we'd find out if
"Service" has something to do with it, or indeed there is something funny
with the code.

- Sahil Malik
http://dotnetjunkies.com/weblog/sahilmalik
 
I tried the trick and while running it as a normal windows application it
worked fine, all events came as they should.
When running it as a service I still don't get any events.
I tried both with .NET 1.1 and .NET 2.0 (2005 beta 1), and they produced the
same result.

Can there be a problem with message looping etc?

/Morgan L



Sahil Malik said:
Try this trick

http://dotnetjunkies.com/WebLog/sahilmalik/archive/2004/12/06/35295.aspx

To help you diagnose/debug your windows service like a windows app. Check
and see if the delegate is null for any crazy reason.

Also, by doing the above, and running it in debugmode, you are essentially
then running a windows application/not a service - that way we'd find out
if "Service" has something to do with it, or indeed there is something
funny with the code.

- Sahil Malik
http://dotnetjunkies.com/weblog/sahilmalik


ML said:
Hello,

I have some small code that opens a connection to an oledb-provider and
opens a recordset. Then creates a delegate to a RecordChangeComplete
event on the recordset.
When I put this code in a service (have tried both OnStart and in a
separate thread) I never get any RecordChangeComplete events. Although
using the exact same code in a form application the event works fine.
In both cases I can see that the oledb-provider is sending the right
events, but it seems they are trapped by the service somehow.

I have used the provider in services (written in C++) before, but never
using ADO / ADO.NET and it has always worked fine.

So what is ADO doing that behaves differently in a service-application
than in a Forms-application?

The code in the service looks like this:

protected override void OnStart(string[] args)
{
m_cn = new Connection();
m_rs = new Recordset();
m_cn.Open(Providerstring, "", "", 0);
m_rs.Open(Tablestring, m_cn, CursorTypeEnum.adOpenDynamic,
LockTypeEnum.adLockReadOnly, 0);
ADODB.RecordsetEvents_RecordChangeCompleteEventHandler
delRecordComplete = new
RecordsetEvents_RecordChangeCompleteEventHandler(RecordChangeComplete);
m_rs.RecordChangeComplete += delRecordComplete;
}

/Morgan L
Click to expand...
Click to expand...
 
I've written windows services with events before and didn't find any strange
peculiarities as far as events go .. I'm perplexed on this one !!!

- Sahil Malik
http://dotnetjunkies.com/weblog/sahilmalik


ML said:
I tried the trick and while running it as a normal windows application it
worked fine, all events came as they should.
When running it as a service I still don't get any events.
I tried both with .NET 1.1 and .NET 2.0 (2005 beta 1), and they produced
the same result.

Can there be a problem with message looping etc?

/Morgan L



Sahil Malik said:
Try this trick

http://dotnetjunkies.com/WebLog/sahilmalik/archive/2004/12/06/35295.aspx

To help you diagnose/debug your windows service like a windows app. Check
and see if the delegate is null for any crazy reason.

Also, by doing the above, and running it in debugmode, you are
essentially then running a windows application/not a service - that way
we'd find out if "Service" has something to do with it, or indeed there
is something funny with the code.

- Sahil Malik
http://dotnetjunkies.com/weblog/sahilmalik


ML said:
Hello,

I have some small code that opens a connection to an oledb-provider and
opens a recordset. Then creates a delegate to a RecordChangeComplete
event on the recordset.
When I put this code in a service (have tried both OnStart and in a
separate thread) I never get any RecordChangeComplete events. Although
using the exact same code in a form application the event works fine.
In both cases I can see that the oledb-provider is sending the right
events, but it seems they are trapped by the service somehow.

I have used the provider in services (written in C++) before, but never
using ADO / ADO.NET and it has always worked fine.

So what is ADO doing that behaves differently in a service-application
than in a Forms-application?

The code in the service looks like this:

protected override void OnStart(string[] args)
{
m_cn = new Connection();
m_rs = new Recordset();
m_cn.Open(Providerstring, "", "", 0);
m_rs.Open(Tablestring, m_cn, CursorTypeEnum.adOpenDynamic,
LockTypeEnum.adLockReadOnly, 0);
ADODB.RecordsetEvents_RecordChangeCompleteEventHandler
delRecordComplete = new
RecordsetEvents_RecordChangeCompleteEventHandler(RecordChangeComplete);
m_rs.RecordChangeComplete += delRecordComplete;
}

/Morgan L
Click to expand...
Click to expand...
Click to expand...
 
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