Conflicting method names in C#

The following example shows two ways of resolving this problem.

MyClass implements IFace and IFace2 both of which have a void parameterless method called MyMethod(). Both interface methods are mapped by the C# compiler to a single implementation of MyMethod. This is only possible if the methods have the same signature and return type.

MyClass2 also implements IFace and IFace2. However, this time it implements MyMethod() explicitly for each interface. This means that you can have separate implementations for each interface but you can only call MyMethod via an IFace or IFace2 reference - not via a MyClass2 reference:

using System;

interface IFace

{

void MyMethod();

}

interface IFace2

{

void MyMethod();

}

class MyClass : IFace, IFace2

{

public void MyMethod()

{

Console.WriteLine("I implement IFace.MyMethod and IFace2.MyMethod");

}

class MyClass2 : IFace, IFace2

{

void IFace.MyMethod()

{

Console.WriteLine("I implement IFace.MyMethod");

}

void IFace2.MyMethod()

{

Console.WriteLine("I implement IFace2.MyMethod");

}

class Test

{

static void Main()

{

MyClass mc = new MyClass();

mc.MyMethod();

MyClass2 mc2 = new MyClass2();

((IFace)mc2).MyMethod();

((IFace2)mc2).MyMethod();

Console.ReadKey();

}

1 Reply

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Vulpes14y ago
Accepted answer
The following example shows two ways of resolving this problem.

MyClass implements IFace and IFace2 both of which have a void parameterless method called MyMethod(). Both interface methods are mapped by the C# compiler to a single implementation of MyMethod. This is only possible if the methods have the same signature and return type.

MyClass2 also implements IFace and IFace2. However, this time it implements MyMethod() explicitly for each interface. This means that you can have separate implementations for each interface but you can only call MyMethod via an IFace or IFace2 reference - not via a MyClass2 reference:

using System;

interface IFace
{
void MyMethod();
}

interface IFace2
{
void MyMethod();
}

class MyClass : IFace, IFace2
{
public void MyMethod()
{
Console.WriteLine("I implement IFace.MyMethod and IFace2.MyMethod");
}
}

class MyClass2 : IFace, IFace2
{
void IFace.MyMethod()
{
Console.WriteLine("I implement IFace.MyMethod");
}

void IFace2.MyMethod()
{
Console.WriteLine("I implement IFace2.MyMethod");
}
}

class Test
{
static void Main()
{
MyClass mc = new MyClass();
mc.MyMethod();
MyClass2 mc2 = new MyClass2();
((IFace)mc2).MyMethod();
((IFace2)mc2).MyMethod();
Console.ReadKey();
}
}