Explicit virtual interfaces

  • Thread starter Thread starter amaca
  • Start date Start date
A

amaca

This does what I expect (as it should, it's from Hoffman and Kruger's C#
Unleashed):

public interface ISpeak
{
void Speak();
}

public abstract class Animal : ISpeak
{
public abstract void Speak();
}

public class Dog : Animal
{
public override void Speak()
{
Console.WriteLine( "Woof" );
}
}

public class Cat : Animal
{
public override void Speak()
{
Console.WriteLine( "Meow" );
}
}


that is, it allows me to define an interface, implement it in a base class
as an abstract method, and then override that method in an inherited class.
But I need to implement two interfaces with the same signature, and this
doesn't compile:

public interface ISpeak
{
void Speak();
}

public abstract class Animal : ISpeak
{
abstract void ISpeak.Speak(); // abstract not allowed
}

class Dog : Animal, ISpeak
{
override void ISpeak.Speak() // override not allowed
{
Console.WriteLine( "Woof" );
}
}

public class Cat : Animal
{
public override void Speak()
{
Console.WriteLine( "Meow" );
}
}

Is this simply not allowed (in which case why not?) or is there some arcane
syntax to allow this?

TIA

Andrew
 
amaca wrote:

But I need to implement two interfaces with the same signature, and this
doesn't compile:
Click to expand...

Do you want to use the same implementation for both interfaces? If so,
I'd create a new abstract method in the base class (eg SpeakImpl) and
implement the two interfaces in a way which calls SpeakImpl.

Jon
 
Do you want to use the same implementation for both interfaces? If so,
I'd create a new abstract method in the base class (eg SpeakImpl) and
implement the two interfaces in a way which calls SpeakImpl.
Click to expand...

Actually no, but it does seem the obviously easy way to go, so I'll do that.
Thanks.

Andrew
 
Hi,

You will need to use explicit declaration:

public interface ISpeak{ void A();}

abstract class C1:ISpeak
{
public abstract void A();

void ISpeak.A()
{
}

}
class C2:C1, ISpeak
{
public override void A()
{

}

void ISpeak.A()
{
}

}
 
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