implementing generic interfaces in c#

Question

how can we inherit generic interfaces in to a generic class? I have tried below code and getting error message: "Bc' does not implement interface member 'ConsoleApplication3.iB.showval(int, int)". How it could be solved?

interface iB<X, Y> 
{
    void storeval(X p1,Y p2);
    void getval();
}
class Bc<X,Y>:iB<int,int>
{
    private X _dm1;
    private Y _dm2;
    public void storeval(X p1,Y p2) 
    {
        this._dm1 = p1;
        this._dm2 = p2;
    }
    public void getval() 
    {
        Console.WriteLine("{0}\t{1}",this._dm1,this._dm2);
    }
}
class Program
{
    static void Main(string[] args)
    {
        Bc<string, bool> b1 = new Bc<string, bool>();
        b1.storeval("AppScienti",true);
        b1.getval();
        Console.ReadKey();
    }
}

Sergey Kalinichenko · Accepted Answer · 2014-04-19 11:48:58Z

3

Your code is not inheriting a generic interface - it inherits a fully defined instance of a generic interface.

Since you inherit iB<int,int>, you need to implement

public void storeval(int p1, int p2) {
    ...
}

Alternatively, you could inherit iB<X,Y>, in which case your implementation of the interface would have worked:

class Bc<X,Y> : iB<X,Y> {
    ...
}

In either case, the parameters of the interface methods dependent on type parameters of the generic interface need to match the type parameters that you specify when inheriting the interface.

answered Apr 19, 2014 at 11:48

Sergey Kalinichenko

729k85 gold badges1.2k silver badges1.6k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

CodeCaster · Accepted Answer · 2014-04-19 11:54:32Z

0

With class Bc<X, Y> : iB<int, int> you define a new generic class, with two new generic type parameters, that happens to implement iB<int, int>. It's more clear if you rename them: class Bc<NewX, NewY> : iB<int, int>.

Your two new generic type parameters have nothing to do with the parameters defined by the interface. You can now declare a new Bc<string, bool> variable while the class still implements iB<int, int>.

You'll have to alter your method signature to let it implement iB<int, int>.storeval(int, int):

public void storeval(int p1, int p2)

If you change your Bc class to inherit the generic parameters like this:

class Bc<X, Y> : iB<X, Y>

You can instantiate one like this:

var bcInt = new Bc<int, int>();

edited Apr 19, 2014 at 11:54

answered Apr 19, 2014 at 11:49

CodeCaster

153k24 gold badges237 silver badges287 bronze badges

Collectives™ on Stack Overflow

implementing generic interfaces in c#

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related