dotnet distributed apps: I have some doubts about object oriented development using
COM+.
To use COM+ my classes must inherits from
System.EnterpriseServices.ServicedComponent. With C# a
class can inherit only from one class. This means that I
can't have these classes:

public class Order
{
public virtual void Create()
{
// insert a record in orders table
}
}

public class SpecialOrder : Order
{
public void Create()
{
// create a order
base.Create();

// Process the special order by example
// approve the order. Insert another table.
this.Approve();
}
}

Any suggestions?
I think in use ADO.Net transactions but with this solution
I don't need COM+ for anything.

Thanks in advanced,

Paulo Monteiro

Paulo,
I have not used COM+ a lot, however you should be able to have Order inherit
from ServicedComponent, then SpecialOrder inherit from Order.

using System.EnterpriseServices;

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What you cannot do is have SpecialOrder inherit from both ServicedComponent
& Order, as both of those are classes.

Hope this helps
Jay


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Just because the language doesn't provide a keyword for multiple inheritance
doesn't mean you can't use it.

First of all, you can implement as many interfaces as you need in addition
to inheriting from a base class. If you really need the functionality of
multiple base classes, use containment, i.e.

class Derived : MyBase, ISomeInterface, IAnotherInterface
{
private SomeOtherBaseClass b;
public void SomeMethodFromB()
{
b.SomeMethodFromB();
}
}

Not as perty as if the class provided a keyword for multiple inheritance,
but that should not limit you if you need to do it.

In your case you don't really seem to need multiple inheritance. Try this

public class Order : System.EnterpriseServices.ServicedComponent
{
// ...
}

public class SpecialOrder : Order
{
// ...
}

or am I missing something?

Eric

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