Base keyword - HELP

[Krishnan]

Hi,
Am having a base class that implements an interface (air code) :

class BaseClass : SomeInterface
{
void SomeInterface.ImplMethod()
{
// -- code here --
}
}

class Derived : SomeInterface
{
void SomeInterface.ImplMethod()
{
//NEED TO CALL BASE'S IMPLEMENTATION HERE
// -- code here --
}
}

Without making the implementations public, is there a way to do it?

TIA
Krishnan

[Wessel Troost]

> class BaseClass : SomeInterface

class Derived : SomeInterface

The derived class doesn't inherit from the base class?

However, even when inheriting, I couldn't find a way to call the base
class interface function. Maybe someone else knows how to do it?

I only found this work-around, by moving the code to a helper function.
Like this:

interface SomeInterface
{
void ImplMethod();
}

class BaseClass : SomeInterface
{
protected void Method() { /* Code goes here */ }
void SomeInterface.ImplMethod() { Method() }
}

class Derived : BaseClass, SomeInterface
{
void SomeInterface.ImplMethod() { base.Method(); }
}

Greetings,
Wessel

[Mattias Sjögren]

>Without making the implementations public, is there a way to do it?

Your naming is a bit confusing since Derived doen't derive from
BaseClass. But you can do

SomeInterface si = new BaseClass();
si.ImplMethod();

if that's what you want.

Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[cody]

You could make the method internal if both classes are in the same assembly
or you really derive from that class and make the method protected.

"Krishnan" <kr*********************@myrealbox.com> schrieb im Newsbeitrag
news:eO**************@tk2msftngp13.phx.gbl...

Hi,
Am having a base class that implements an interface (air code) :

class BaseClass : SomeInterface
{
void SomeInterface.ImplMethod()
{
// -- code here --
}
}

class Derived : SomeInterface
{
void SomeInterface.ImplMethod()
{
//NEED TO CALL BASE'S IMPLEMENTATION HERE
// -- code here --
}
}

Without making the implementations public, is there a way to do it?

TIA
Krishnan

[Krishnan]

Thanks for the reply. I missed out on mentioning the base class inheritance
in the derived class.
"Wessel Troost" <no****@like.the.sun> wrote in message
news:op.styc180rxgtv7i@asbel...

class BaseClass : SomeInterface
class Derived : SomeInterface

The derived class doesn't inherit from the base class?

However, even when inheriting, I couldn't find a way to call the base
class interface function. Maybe someone else knows how to do it?

I only found this work-around, by moving the code to a helper function.
Like this:

interface SomeInterface
{
void ImplMethod();
}

class BaseClass : SomeInterface
{
protected void Method() { /* Code goes here */ }
void SomeInterface.ImplMethod() { Method() }
}

class Derived : BaseClass, SomeInterface
{
void SomeInterface.ImplMethod() { base.Method(); }
}

Greetings,
Wessel

[Krishnan]

Just one Q. The line,

void SomeInterface.ImplMethod() { Method() }

would call the most derived version's method, right? I mean there is no
"MyClass" keyword in C# :(

TIA
Krishnan
Krishnan "Pay your tax with a smile", says the government. I tried. They
wanted cash.
"Wessel Troost" <no****@like.the.sun> wrote in message
news:op.styc180rxgtv7i@asbel...

class BaseClass : SomeInterface
class Derived : SomeInterface

The derived class doesn't inherit from the base class?

However, even when inheriting, I couldn't find a way to call the base
class interface function. Maybe someone else knows how to do it?

I only found this work-around, by moving the code to a helper function.
Like this:

interface SomeInterface
{
void ImplMethod();
}

class BaseClass : SomeInterface
{
protected void Method() { /* Code goes here */ }
void SomeInterface.ImplMethod() { Method() }
}

class Derived : BaseClass, SomeInterface
{
void SomeInterface.ImplMethod() { base.Method(); }
}

Greetings,
Wessel

[Marko Becirevic]

> class Derived : SomeInterface

{
void SomeInterface.ImplMethod()
{
//NEED TO CALL BASE'S IMPLEMENTATION HERE
base.ImplMethod();
// -- code here --
}
}

[Wessel Troost]

> Just one Q. The line,

void SomeInterface.ImplMethod() { Method() }

would call the most derived version's method, right? I mean there is no
"MyClass" keyword in C# :(

C# does have a "MyClass" keyword: this. You could write:

void SomeInterface.ImplMethod() { this.Method() }

Greetings,
Wessel

[Wessel Troost]

> base.ImplMethod();

That doesn't work. Try it.

Greetings,
Wessel

[Christof Nordiek]

"Krishnan" <kr*********************@myrealbox.com> schrieb im Newsbeitrag
news:eM**************@tk2msftngp13.phx.gbl...

Just one Q. The line,

void SomeInterface.ImplMethod() { Method() }

would call the most derived version's method, right? I mean there is no
"MyClass" keyword in C# :(

Why this would be a problem?
In the code of Wessel Troost BaseClass.Method is not virtual, so there never
will be a more derived version.

Christof

[Adam Clauss]

Wait, so Dervied DOES or does NOT derive from class Base?

If it does, just use:

base.ImplMethod();

--
Adam Clauss

"Krishnan" <kr*********************@myrealbox.com> wrote in message
news:OR****************@TK2MSFTNGP15.phx.gbl...

Thanks for the reply. I missed out on mentioning the base class
inheritance in the derived class.
"Wessel Troost" <no****@like.the.sun> wrote in message
news:op.styc180rxgtv7i@asbel...

class BaseClass : SomeInterface
class Derived : SomeInterface

The derived class doesn't inherit from the base class?

However, even when inheriting, I couldn't find a way to call the base
class interface function. Maybe someone else knows how to do it?

I only found this work-around, by moving the code to a helper function.
Like this:

interface SomeInterface
{
void ImplMethod();
}

class BaseClass : SomeInterface
{
protected void Method() { /* Code goes here */ }
void SomeInterface.ImplMethod() { Method() }
}

class Derived : BaseClass, SomeInterface
{
void SomeInterface.ImplMethod() { base.Method(); }
}

Greetings,
Wessel

[Wessel Troost]

> Wait, so Dervied DOES or does NOT derive from class Base?

If it does, just use:

base.ImplMethod();

For some reason, that doesn't work if ImplMethod is an interface method.

Greetings,
Wessel

[Adam Clauss]

The following works just fine, just tried it (note - if Derived derives from
BaseClass, as mine does then ImplMethod must either be marked as new in
Derived, or virtual in base/override in Derived.):

public interface SomeInterface
{
void ImplMethod();
}
public class BaseClass : SomeInterface
{
public void ImplMethod()
{
Console.WriteLine("BaseClass.ImplMethod");
}
}
public class Derived : BaseClass
{
public new void ImplMethod()
{
base.ImplMethod();
Console.WriteLine("Derived.BaseClass");
}
}

--
Adam Clauss

"Wessel Troost" <no****@like.the.sun> wrote in message
news:op.styi8yiixgtv7i@asbel...

Wait, so Dervied DOES or does NOT derive from class Base?
If it does, just use:

base.ImplMethod();

For some reason, that doesn't work if ImplMethod is an interface method.

Greetings,
Wessel

[Christof Nordiek]

"Adam Clauss" <ca*****@tamu.edu> schrieb im Newsbeitrag
news:11*************@corp.supernews.com...

The following works just fine, just tried it (note - if Derived derives
from BaseClass, as mine does then ImplMethod must either be marked as new
in Derived, or virtual in base/override in Derived.):

public interface SomeInterface
{
void ImplMethod();
}
public class BaseClass : SomeInterface
{
public void ImplMethod()
{
Console.WriteLine("BaseClass.ImplMethod");
}
}
public class Derived : BaseClass
{
public new void ImplMethod()
{
base.ImplMethod();
Console.WriteLine("Derived.BaseClass");
}
}

--
Adam Clauss

Yes, but that's implicit member implementation and the memeber is public.
The OP said it shall not be public, so he has to use explicit member
implementation.

Christof

[Wessel Troost]

> ImplMethod must either be marked as new in Derived, or virtual in

base/override in Derived.

Thanks, that was the information I was missing.

Greetings,
Wessel

[Krishnan]

Oh yes. You are right. I tried a similar workaround with the method marked
virtual and had a confusion. This should work fine (and actually, so should
my case ;) ).

Thanks a ton.

Krishnan

"Christof Nordiek" <[e-mail]> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...

"Krishnan" <kr*********************@myrealbox.com> schrieb im Newsbeitrag
news:eM**************@tk2msftngp13.phx.gbl...

Just one Q. The line,

void SomeInterface.ImplMethod() { Method() }

would call the most derived version's method, right? I mean there is no
"MyClass" keyword in C# :(

Why this would be a problem?
In the code of Wessel Troost BaseClass.Method is not virtual, so there
never will be a more derived version.

Christof

[Adam Clauss]

"Christof Nordiek" <[e-mail]> wrote in message
news:uf**************@TK2MSFTNGP12.phx.gbl...

Yes, but that's implicit member implementation and the memeber is public.
The OP said it shall not be public, so he has to use explicit member
implementation.

Huh? It's an interface method. It MUST be public. There is no other kind.

--
Adam Clauss

[Jon Skeet [C# MVP]]

Adam Clauss <ca*****@tamu.edu> wrote:

"Christof Nordiek" <[e-mail]> wrote in message
news:uf**************@TK2MSFTNGP12.phx.gbl...

Yes, but that's implicit member implementation and the memeber is public.
The OP said it shall not be public, so he has to use explicit member
implementation.

Huh? It's an interface method. It MUST be public. There is no other kind.

No - if you use explicit interface implementation you end up with a
method which is sort of public and sort of private.

From the language spec:

<quote>
Explicit interface member implementations have different accessibility
characteristics than other members. Because explicit interface member
implementations are never accessible through their fully qualified name
in a method invocation or a property access, they are in a sense
private. However, since they can be accessed through an interface
instance, they are in a sense also public.
</quote>

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too