Extendind/hooking system dll's

[yairinbal]

Hello,

I am looking for a way to extend system classes (specifically I'm
talking about data provider connection classes such as
System.Data.SqlConnection, System.Data.OracleConnection).

What I need is to add custom pre-processing before call to some of teh
methods. I would like to minimize the code changes of the application
that uses these classes.

The problem is that these system classes are defnied as sealed so I
cannot simply extend them.

Do you have any idea how can I extended these classes and more
generally how can I hook system classes?

Regards,
Yair

[Jesse Houwing]

* ya*******@yahoo.com wrote, On 22-7-2007 16:08:

Hello,

I am looking for a way to extend system classes (specifically I'm
talking about data provider connection classes such as
System.Data.SqlConnection, System.Data.OracleConnection).

What I need is to add custom pre-processing before call to some of teh
methods. I would like to minimize the code changes of the application
that uses these classes.

The problem is that these system classes are defnied as sealed so I
cannot simply extend them.

Do you have any idea how can I extended these classes and more
generally how can I hook system classes?

Regards,
Yair

You could 'wrap' them. Implement IDBConnection, put a SqlConnection in
your class as private field and forward every call & property. This
also gives you a nice processing point.

Jesse

[yairinbal]

On Jul 22, 5:48 pm, Jesse Houwing <[e-mail]>
wrote:

* [e-mail] wrote, On 22-7-2007 16:08:

Hello,

I am looking for a way to extend system classes (specifically I'm
talking about data provider connection classes such as
System.Data.SqlConnection, System.Data.OracleConnection).

What I need is to add custom pre-processing before call to some of teh
methods. I would like to minimize the code changes of the application
that uses these classes.

The problem is that these system classes are defnied as sealed so I
cannot simply extend them.

Do you have any idea how can I extended these classes and more
generally how can I hook system classes?

Regards,
Yair

You could 'wrap' them. Implement IDBConnection, put a SqlConnection in
your class as private field and forward every call & property. This
also gives you a nice processing point.

Jesse- Hide quoted text -

- Show quoted text -

Hi,
I thought about that idea but I found the following drawbacks:

1. The database specific classes (e.g. SqlConnection,
OracleConnecitoon) may have database specific methods and wrapping
IDBConnection may cause loss of functionallity
2. My applicaiton currently work with SqlConneciton/OracleConection
classes. Since the new class is not superclass of these classes, I
cannot move it as arguments to methods that expect it. I could
implement casting and returning the private field but doing so will
bypass my wrapping.

What I am acutally need as a way to "bypass" the sealed...

Do you have any ideas?

Yair

[Nicholas Paldino [.NET/C# MVP]]

Yair,

Quite simply, if the class is sealed, then you can't do anything. The
best thing you could do in the case of the provider classes is implement the
interface classes that all data providers use (IDbCommand, IDbConnection)
and code your app to use those. Then, you can basically host instances of
the sealed database classes inside of your interface implementations, and
perform the calls as you wish).

I am curious, what kind of interception do you need to perform?

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

<ya*******@yahoo.comwrote in message
news:11**********************@g4g2000hsf.googlegro ups.com...

Hello,

I am looking for a way to extend system classes (specifically I'm
talking about data provider connection classes such as
System.Data.SqlConnection, System.Data.OracleConnection).

What I need is to add custom pre-processing before call to some of teh
methods. I would like to minimize the code changes of the application
that uses these classes.

The problem is that these system classes are defnied as sealed so I
cannot simply extend them.

Do you have any idea how can I extended these classes and more
generally how can I hook system classes?

Regards,
Yair

[yairinbal]

On Jul 23, 4:49 am, "Nicholas Paldino [.NET/C# MVP]"
<[e-mail]:

Yair,

Quite simply, if the class is sealed, then you can't do anything. The
best thing you could do in the case of the provider classes is implement the
interface classes that all data providers use (IDbCommand, IDbConnection)
and code your app to use those. Then, you can basically host instances of
the sealed database classes inside of your interface implementations, and
perform the calls as you wish).

I am curious, what kind of interception do you need to perform?

--
- Nicholas Paldino [.NET/C# MVP]
- [e-mail]

<[e-mail] in message

news:11**********************@g4g2000hsf.googlegro ups.com...

Hello,

I am looking for a way to extend system classes (specifically I'm
talking about data provider connection classes such as
System.Data.SqlConnection, System.Data.OracleConnection).

What I need is to add custom pre-processing before call to some of teh
methods. I would like to minimize the code changes of the application
that uses these classes.

The problem is that these system classes are defnied as sealed so I
cannot simply extend them.

Do you have any idea how can I extended these classes and more
generally how can I hook system classes?

Regards,
Yair- Hide quoted text -

- Show quoted text -

Hi,

I guess that the solution you suggested will require mass code change.
For example - if currently my connection object is defined as
OracleConnection, I'll now have to change it to MyConnection.

I needed to add transparent logging capabiliies to the Open() of
DbConnection method. I wanted it to work with the need to change all
may apps.

Yair