Share Data Between Classes

[cksj]

I'm working on a VB.Net DLL project. It has 6 classes. One of the classes
has the properties for the database path, database name and server name. The
purpose of this class is so that the DLL can be tested on different servers.
Without using the keyword "Shared", how can I share these data to the other
5 classes?

Thanks for any ideas!

Cesar

[Jay B. Harlow [MVP - Outlook]]

Re: Share Data Between Classes

Cesar,
Oh! out of curiosity, why do you not want to use "Shared"?

Hope this helps
Jay

"cksj" <cksanjose@hotm ail.com> wrote in message
news:%23Zgygrxd DHA.3280@tk2msf tngp13.phx.gbl. ..[color=blue]
> I'm working on a VB.Net DLL project. It has 6 classes. One of the classes
> has the properties for the database path, database name and server name.[/color]
The[color=blue]
> purpose of this class is so that the DLL can be tested on different[/color]
servers.[color=blue]
> Without using the keyword "Shared", how can I share these data to the[/color]
other[color=blue]
> 5 classes?
>
> Thanks for any ideas!
>
> Cesar
>
>[/color]

[Jay B. Harlow [MVP - Outlook]]

Re: Share Data Between Classes

Cesar,
Without Shared, each consumer of the class will need to create an instance
of the class then access the properties. Which for this sort of thing the
Singleton Pattern is better, you do however need to use Shared to implement
a Singleton.

You could make the class itself a Singleton, when means the properties will
not be marked shared, however a read only shared Instance field will be
created in the class.

Public Class DbSettings

Public Shared Readonly Instance As New DbSettings()

Private Sub New()
End Sub

Public Property DatabasePath...

End Class

Then whenever you need to use any of the properties of the class you use
DbSettings.Inst ance.DatabasePa th.

Hope this helps
Jay

"cksj" <cksanjose@hotm ail.com> wrote in message
news:%23Zgygrxd DHA.3280@tk2msf tngp13.phx.gbl. ..[color=blue]
> I'm working on a VB.Net DLL project. It has 6 classes. One of the classes
> has the properties for the database path, database name and server name.[/color]
The[color=blue]
> purpose of this class is so that the DLL can be tested on different[/color]
servers.[color=blue]
> Without using the keyword "Shared", how can I share these data to the[/color]
other[color=blue]
> 5 classes?
>
> Thanks for any ideas!
>
> Cesar
>
>[/color]

[Don Nablo]

Re: Share Data Between Classes

If you have a dbconnection object that you want the other 5 classes to use
the classic approach would be to just dim the db class object and pass it
along to each method that requires in in the other classes

so you would just have a method like

public function getItem(ses as dbconnection, itemCode as string) as class1


"cksj" <cksanjose@hotm ail.com> wrote in message
news:#ZgygrxdDH A.3280@tk2msftn gp13.phx.gbl...[color=blue]
> I'm working on a VB.Net DLL project. It has 6 classes. One of the classes
> has the properties for the database path, database name and server name.[/color]
The[color=blue]
> purpose of this class is so that the DLL can be tested on different[/color]
servers.[color=blue]
> Without using the keyword "Shared", how can I share these data to the[/color]
other[color=blue]
> 5 classes?
>
> Thanks for any ideas!
>
> Cesar
>
>[/color]

[cksj]

Re: Share Data Between Classes

Jay,

Thanks for your help.
I read that using Shared in DLL is not the best practice to use.

Cesar

"Jay B. Harlow [MVP - Outlook]" <Jay_Harlow@ema il.msn.com> wrote in message
news:OSF85GydDH A.1620@TK2MSFTN GP12.phx.gbl...[color=blue]
> Cesar,
> Oh! out of curiosity, why do you not want to use "Shared"?
>
> Hope this helps
> Jay
>
> "cksj" <cksanjose@hotm ail.com> wrote in message
> news:%23Zgygrxd DHA.3280@tk2msf tngp13.phx.gbl. ..[color=green]
> > I'm working on a VB.Net DLL project. It has 6 classes. One of the[/color][/color]
classes[color=blue][color=green]
> > has the properties for the database path, database name and server name.[/color]
> The[color=green]
> > purpose of this class is so that the DLL can be tested on different[/color]
> servers.[color=green]
> > Without using the keyword "Shared", how can I share these data to the[/color]
> other[color=green]
> > 5 classes?
> >
> > Thanks for any ideas!
> >
> > Cesar
> >
> >[/color]
>
>[/color]

[Jay B. Harlow [MVP - Outlook]]

Re: Share Data Between Classes

Cesar,[color=blue]
> I read that using Shared in DLL is not the best practice to use.[/color]
Correct Shared should not be your first choice, however there are times when
it is appropriate. It depends on the type of app. Like any construct
available in .NET its usage has its pros & cons.

As I said in my other email, you need to use it for the Singleton Pattern,
what you asked sounds like a good application of the Singleton Pattern,
assuming this is not an ASP.NET app. ASP.NET apps you need to use session &
context aware methods of implementing a singleton. Which is where public
shared methods (properties, subs & functions) are better than public shared
fields. You can change the code of the method to better anticipate the
environment you are running it.

The Singleton Pattern is a common OOP Design Pattern to allow global access
to an object. For details on the Singleton Patten and other Design Patterns
see:
1. "Design Patterns - Elements of Reusable Object-Oriented Software" by the
GOF (Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides)
2. "Patterns of Enterprise Application Architecture" by Martin Fowler
3. "Visual Basic Design Patterns - VB 6.0 and VB.NET" by James W. Cooper.

#3 is a good companion for #1, #2 shows some advanced patterns. All three
are from Addison Wesley.

Hope this helps
Jay

"cksj" <cksanjose@hotm ail.com> wrote in message
news:eyRkqO6dDH A.2368@TK2MSFTN GP09.phx.gbl...[color=blue]
> Jay,
>
> Thanks for your help.
> I read that using Shared in DLL is not the best practice to use.
>
> Cesar
>
> "Jay B. Harlow [MVP - Outlook]" <Jay_Harlow@ema il.msn.com> wrote in[/color]
message[color=blue]
> news:OSF85GydDH A.1620@TK2MSFTN GP12.phx.gbl...[color=green]
> > Cesar,
> > Oh! out of curiosity, why do you not want to use "Shared"?
> >
> > Hope this helps
> > Jay
> >
> > "cksj" <cksanjose@hotm ail.com> wrote in message
> > news:%23Zgygrxd DHA.3280@tk2msf tngp13.phx.gbl. ..[color=darkred]
> > > I'm working on a VB.Net DLL project. It has 6 classes. One of the[/color][/color]
> classes[color=green][color=darkred]
> > > has the properties for the database path, database name and server[/color][/color][/color]
name.[color=blue][color=green]
> > The[color=darkred]
> > > purpose of this class is so that the DLL can be tested on different[/color]
> > servers.[color=darkred]
> > > Without using the keyword "Shared", how can I share these data to the[/color]
> > other[color=darkred]
> > > 5 classes?
> > >
> > > Thanks for any ideas!
> > >
> > > Cesar
> > >
> > >[/color]
> >
> >[/color]
>
>[/color]