Custom Event Logging / Shared Class

  • Thread starter Thread starter CJ Taylor
  • Start date Start date
C

CJ Taylor

Hey all,

This is probably a dumb question, but still feeling a little strange from
Labor day festiviities. Anyways,

I want a shared sub, at least something that is easy to call from any one of
my classes within the scope of my project (or that which inherits/imports
this class).

Basically, want them to be able to call a sub defined as

Public Shared Sub LogEvent (sender as object, e as
MWC.BCTransfer.Logger.LogEventArgs)

now tihs is fine... but if the UI is active, I want it to push information
to a listview I have.

Now I can call the LogEvent routine fine, but if I try to access a UI
function, I obviuosly can't.

How do I get around this?

Thanks,
CJ
 
Hi,
You cannot call non shared members of a class from the shared method
without making an instance of it and then calling it on that instance.

Cheers
Benny
 
Thanks benny,

I was sure on that part, but does anyone know of a method to do this? Like
to write a good / simple event logger?

I suppose I could do inherited stuff, but I was hoping for something
simplier.

Thanks,
CJ
 
Now I can call the LogEvent routine fine, but if I try to access a UI
function, I obviuosly can't.

How do I get around this?
Click to expand...

Why would you want to? That's the real question... The fact that you hit a
wall is just an indicator that you are trying to break the rules of "good
OOP" design (or whatever). You have:

Logger.Log(o, e) - Takes in a source object, logs an event

This is the object you use for storing information, I would say that you are
trying to mix your data/information with your UI, and this is generally bad.
The alternative would be to log the information (storing it in however you
want), and then provide access to that log data via some shared Property or
Method, then your UI is still independant of your information:

Public Class Logger
Public Shared Sub LogEvent( sender as Object, e as LogEventArgs)
...
RaiseEvent LogAdded(...)
End Sub

Public Shared Property EntryCount as Integer
Public Default ReadOnly Shared Property Item(index as Integer) as
LogObject
End Class

Now when your list updates, it can just read the Item property of the
logger:

'// Client Code
ListView.BeginUpdate
ListView.Items.Clear

For I as Integer = 0 to Logger.EntryCount
ListView.Items.Add ( log )
Next

ListView.EndUpdate


What do you think?

~
Jeremy
 
Perfect Jeremy,

That was the goal, I was just struggling a little this morning to think
about how I wanted to do it...

Also, I think that because I'm doing this within a separated DLL, I'll do it
kinda like how MSCOMCTL was done in the past, where I will raise my own
dialogs as well, kinda like a built in UI to the DLL so its uniform, but
also make the Loglist (XML Data of the logged events) public readonly that
way other applications can get a handler on it, and add an event like you
said to say when its raised, another UI that is wrapping that DLL can be
notified, and therefore, pull updated event data...

I could see where this could become cumbersome (especially if you had large
amounts of Event Data), so maybe even add a property about 'last event
added." or something...

I don't know... thoughts?

-CJ
 
I could see where this could become cumbersome (especially if you had
large
amounts of Event Data), so maybe even add a property about 'last event
added." or something...

I don't know... thoughts?
Click to expand...

You could create an [Before|After]LogEntryAdded event, and make the
EventArgs hold the data for the Entry that was added.

Public Sub logger_LogEntryAdded(o, e) handles x.x
List.Add( e.Entry.ToString( ) )
End Sub

?

~
Jeremy
 
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