Service executes twice

[Tom Van den Brandt]

Hi,

I wrote a simple windows service that includes a FileSystemWatcher.
After building and installing the service (installutil) I notice that
the service executes twice. I included a write to the application
eventlog in OnStart ("service has started and is ready to watch the
filesystem") and this results in two entries in the eventlog.

Also, the handler for the FileSystemWatcher seems to be fired twice if
something happens with a file the service is watching.

I checked the machines services and in the task manager but I see only
one instance of the service running.

I'm a newbie at this, so I probably missed something obvious... Could
this be the properties of the service that were not correctly configured?

Any ideas?

Thx,

Tom

[Harry]

"Tom Van den Brandt" <gu*******@guineapig.bewrote in message
news:uJ**************@TK2MSFTNGP06.phx.gbl...

Hi,

I wrote a simple windows service that includes a FileSystemWatcher.
After building and installing the service (installutil) I notice that
the service executes twice. I included a write to the application
eventlog in OnStart ("service has started and is ready to watch the
filesystem") and this results in two entries in the eventlog.

Also, the handler for the FileSystemWatcher seems to be fired twice if
something happens with a file the service is watching.

I checked the machines services and in the task manager but I see only
one instance of the service running.

I'm a newbie at this, so I probably missed something obvious... Could
this be the properties of the service that were not correctly configured?

Any ideas?

Thx,

Tom

Tom, often we look at code and miss that what we are trying to accomplish is
often sabotaged by lack of observation or object/control events. Two of the
great debugging tools I have discovered are sleep and alcohol. Without
seeing your code, it is not possible to give advice. I have solved many
problems just by putting the problem to bed for a while, and come back to it
when ones' emotional state has changed. Cheers

[Tom Van den Brandt]

Well,

I had some sleep in the meantime...
And this is what I came up with:
I had the code to write to the application event log in OnStart double.
So part of the problem is corrected. Still, the FilesSystemWatcher
seems to fire twice. Maybe I don't understand its mechanics well enough.

This is what I have in OnStart:

Me.SMSFileWatcher.Path = Path
Me.SMSFileWatcher.IncludeSubdirectories = False
Me.SMSFileWatcher.NotifyFilter = IO.NotifyFilters.LastWrite
Me.SMSFileWatcher.Filter = "freebee.jrn"
Me.SMSFileWatcher.EnableRaisingEvents = True
AddHandler SMSFileWatcher.Changed, AddressOf OnChanged

And this in OnChanged:

My.Application.Log.WriteEntry("An SMS has arrived!")
send("An SMS has arrived")

send passes the message to clients on the network...

So, everytime I open the file, change it and save it, I have the "An SMS
has arrived!" message twice in the Application event log.

Am I doing this correctly?

Thx!
Tom
Harry schreef:

"Tom Van den Brandt" <gu*******@guineapig.bewrote in message
news:uJ**************@TK2MSFTNGP06.phx.gbl...

>Hi,

I wrote a simple windows service that includes a FileSystemWatcher.
After building and installing the service (installutil) I notice that
the service executes twice. I included a write to the application
eventlog in OnStart ("service has started and is ready to watch the
filesystem") and this results in two entries in the eventlog.

Also, the handler for the FileSystemWatcher seems to be fired twice if
something happens with a file the service is watching.

I checked the machines services and in the task manager but I see only
one instance of the service running.

I'm a newbie at this, so I probably missed something obvious... Could
this be the properties of the service that were not correctly configured?

Any ideas?

Thx,

Tom

Tom, often we look at code and miss that what we are trying to accomplish is
often sabotaged by lack of observation or object/control events. Two of the
great debugging tools I have discovered are sleep and alcohol. Without
seeing your code, it is not possible to give advice. I have solved many
problems just by putting the problem to bed for a while, and come back to it
when ones' emotional state has changed. Cheers

[Phill W.]

Tom Van den Brandt wrote:

Still, the FilesSystemWatcher seems to fire twice.
Maybe I don't understand its mechanics well enough.

This is what I have in OnStart:

Me.SMSFileWatcher.Path = Path
Me.SMSFileWatcher.IncludeSubdirectories = False
Me.SMSFileWatcher.NotifyFilter = IO.NotifyFilters.LastWrite
Me.SMSFileWatcher.Filter = "freebee.jrn"
Me.SMSFileWatcher.EnableRaisingEvents = True
AddHandler SMSFileWatcher.Changed, AddressOf OnChanged

Did you declare SMSFileWatcher "WithEvents"?

If so, VB will have /automatically/ wired-up the OnChanged Event for you
and your AddHandler statement will simply add /another/ handler to that
event; it won't "undo" or "replace" an existing one.

And this in OnChanged:

I'm not entirely sure why but, whenever I've used the FileSystemWatcher,
I've had to allow for multiple events in rapid succession - you seem to
get duplicate "change" events even if the file only changes once.

HTH,
Phill W.

[Tom Van den Brandt]

Phill W. schreef:

Tom Van den Brandt wrote:

>Still, the FilesSystemWatcher seems to fire twice.
Maybe I don't understand its mechanics well enough.

This is what I have in OnStart:

Me.SMSFileWatcher.Path = Path
Me.SMSFileWatcher.IncludeSubdirectories = False
Me.SMSFileWatcher.NotifyFilter = IO.NotifyFilters.LastWrite
Me.SMSFileWatcher.Filter = "freebee.jrn"
Me.SMSFileWatcher.EnableRaisingEvents = True
AddHandler SMSFileWatcher.Changed, AddressOf OnChanged

Did you declare SMSFileWatcher "WithEvents"?

Even when I comment out the Addhandler line and the EnableRaisingEvents
line (and put the code in OnChanged in
Private Sub SMSFileWatcher_Changed
The code is still executed twice.

I'm thinking that for some reason the filewatcher is firing the event
twice...

Thx for your suggestions!

>
If so, VB will have /automatically/ wired-up the OnChanged Event for you
and your AddHandler statement will simply add /another/ handler to that
event; it won't "undo" or "replace" an existing one.

>And this in OnChanged:

I'm not entirely sure why but, whenever I've used the FileSystemWatcher,
I've had to allow for multiple events in rapid succession - you seem to
get duplicate "change" events even if the file only changes once.

HTH,
Phill W.