how to achieve multiple inheritance using interface but both interface have same method name

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i have two interface with same method name and one class inheriting those interface but when i trying to create object of class and call those interface method, how i come come to know which method will execute first if i call both method..??

Posted 30-Jan-13 23:05pm

mohansahu

Updated 30-Jan-13 23:07pm

v2

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2 solutions

Solution 2

The answer to this question really depends on how you have implemented your interfaces in the class. In other words, have you explicitly and/or implicitly implemented the interfaces. Let's consider a simple example:

C#

public interface IFoo
{
  void SetName(string name);
  int Age { get; set; }
}

public interface IBar
{
  void SetName(string name);
  DateTime DOB { get; set; }
}

public class FooBar : IFoo, IBar
{
  public void SetName(string name)
  {
    Console.WriteLine("Name is " + name);
  }

  public int Age
  {
    get
    {
      throw new NotImplementedException();
    }
    set
    {
      throw new NotImplementedException();
    }
  }

  void IBar.SetName(string name)
  {
    Console.WriteLine("IBar Name is " + name);
  }

  DateTime IBar.DOB
  {
    get
    {
      throw new NotImplementedException();
    }
    set
    {
      throw new NotImplementedException();
    }
  }
}

Now, let's call this like this:

C#

IFoo foo = new FooBar();
foo.SetName("Foo");
IBar bar = new FooBar();
bar.SetName("Bar");

This would produce the output

Name is Foo
IBar Name is Foo

Now, if we don't use the interface to in the instantiation, the explicit implementation is called.

C#

FooBar fooBar = new FooBar();
fooBar.SetName("FooBar");

This produces

Name is FooBar

Okay, so you may be tempted to think that the order of the interfaces in the declaration determines which one is the explicit and which one is the implicit declaration. This is not correct. Let's change our class a bit

public class FooBar : IFoo, IBar
{
  public void SetName(string name)
  {
    Console.WriteLine("Name is " + name);
  }

  int IFoo.Age
  {
    get
    {
      throw new NotImplementedException();
    }
    set
    {
      throw new NotImplementedException();
    }
  }

  void IFoo.SetName(string name)
  {
    Console.WriteLine("IFoo Name is " + name);
  }

  public DateTime DOB
  {
    get
    {
      throw new NotImplementedException();
    }
    set
    {
      throw new NotImplementedException();
    }
  }
}

Now, calling the same code as we did above, we see that the output has changed like this:

IFoo Name is Foo
Name is Bar
Name is FooBar

As you can see, IBar is now the explicit implementation.

Posted 30-Jan-13 23:26pm

Pete O'Hanlon

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Mantu Singh · Accepted Answer · 2013-01-30T23:17:00

Try this

C#

interface I1
   {
       void diap();
   }
   interface I2
   {
       void diap();
   }

class Imp:I1,I2
{

public void I1.diap()
        {
            throw new Exception("The method or operation is not implemented.");
        }           

       
       
        void I2.diap()
        {
            throw new Exception("The method or operation is not implemented.");
        }

}

_______________________________________________________

Now use as follows

C#

Imp f = new Imp();
            I1 i = f;  //I1 interface I1 used to select I1 behaviour use I2 for second interface
            i.diap();

best of luck !!