Multiple inheritence with c#

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Hi

I have one problem i have two interfaces

C#

interface test1
{
void show();
}
interface test2
{
void show();
}

class testing: test1,test2
{
// How to call test1 and test2 method
}

Can any one help me please?

Regards
S. keshaavan

Posted 12-May-12 23:51pm

NK7

Updated 13-May-12 0:19am

Manas Bhardwaj

v2

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5 solutions

Solution 3

OriginalGriff: explicit interface methods should not be public (you will get compile error if you declare any access modifier, but I wonder did you check your code before you wrote the answer?) but it is private by default. The reason being is that these methods should be accessible via the interface reference not via the object of the class.

So, here is how we implement (explicit implementation) the interfaces which happened to be having same methods.

C#

class testing : test1, test2
    {

        void test1.show()
        {
            MessageBox.Show("From interface test1");
        }

        void test2.show()
        {
            MessageBox.Show("From interface test2");
        }
    }

And here is how you access them:

C#

testing t = new testing();

            test1 t1 = t;
            test2 t2 = t;

            t1.show();
            t2.show();

Posted 5-Jul-12 1:44am

Prabu ram

Comments

bbirajdar 5-Jul-12 7:58am

@Prabhu Ram.. You are absolutely correct... The implementation should not be public....It gives the error "Error 1 The modifier 'public' is not valid for this item ....testing.cs " .. My +5

Solution 1

I would have first looked at Google. This has been asked infinte times already.

https://www.google.com/search?sourceid=chrome&ie=UTF-8&q=Multiple+inheritence+c%23&hl=en[^]

Anyway, this thread should help.

http://stackoverflow.com/questions/178333/multiple-inheritance-in-c-sharp[^]

Posted 13-May-12 0:23am

Manas Bhardwaj

Solution 4

Interface 1

C#

public interface test1
{
    void show();
}

Inerface 2

C#

public interface test2
{
    void show();
}

Implementing the interfaces

C#

public class testing: test1,test2
{
	public testing()
	{
		//
		// TODO: Add constructor logic here
		//
	}

    #region test1 Members

    void test1.show()
    {
        throw new NotImplementedException();
    }

    #endregion

    #region test2 Members

    void test2.show()
    {
        throw new NotImplementedException();

    }

    #endregion
}

Creating the object and calling the methods show()

C#

testing test = new testing();
        ((test1)test).show();
        ((test2)test).show();

Posted 5-Jul-12 2:04am

bbirajdar

Solution 5

have a look. May be the scenario explained will help you understand.

scenario is a class contains 5 methods and users are there ,first user need to access first 3 method and 2nd user access remain 2 methods[^]

Posted 5-Jul-12 2:37am

Libish Varghese Jacob

Updated 5-Jul-12 2:46am

v2

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OriginalGriff · Accepted Answer · 2012-05-13T00:30:00

You can't - they are interfaces.
Interface do not define any code, they just declare a contract that the derived class must adhere to by implementing the properties and methods.

You would have to implement the show method in the testing class and then if you needed to explicitly call it, cast your testing instance to test1 or test2:

C#

interface test1
    {
    void show();
    }
interface test2
    {
    void show();
    }

public class testing : test1, test2
    {
    // How to call test1 and test2 method
    public testing()
        {
        ((test1)this).show();
        ((test2)this).show();

        }

    public void test1.show()
        {
        throw new NotImplementedException();
        }

    public void test2.show()
        {
        throw new NotImplementedException();
        }
    }