How to create an instance of an Interface(access to Interface)

Question

I have an Interface like this:

namespace QuickRoutes.Model.Utilities
{
    public interface IRoutesManager
    {
        bool ImportRoute(Stream inputStream, string fileName);
        List<Route> GetAllRoutes();
        List<Route> GetAllRoutesForDate(DateTime from, DateTime to);
        void DeleteRoute(string routeName);
        void DeleteAllRoutes();

    }
}

and I want to access to i.e ImportRoute function from my Form but I cant access to this Function and an error occured like this: cannot create an instance of the abstract class or interface How can I access to these functions?

I think you need to learn OOPS concepts.

Sudhakar B
– Sudhakar B

2012-06-16 10:00:40 +00:00
Commented Jun 16, 2012 at 10:00 — Sudhakar B
– Sudhakar B, Commented Jun 16, 2012 at 10:00

Jon Skeet · Accepted Answer · 2012-06-16 09:59:30Z

3

You need to have an implementation of the interface which defines the actual behaviour. The interface itself only declares the members - as you can see, there's no code there to say what to do.

Your Form can either create an instance of some implementation, or be given it - quite possibly only as an IRoutesManager, so that the form itself doesn't need to care about which implementation it's using.

answered Jun 16, 2012 at 9:59

Jon Skeet

1.5m893 gold badges9.3k silver badges9.3k bronze badges

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

Comments

nyxthulhu · Accepted Answer · 2012-06-16 10:00:42Z

1

You never create instances of interfaces, interfaces are just contracts. What you would do is :-

public class MyRouteManager : IRoutesManager
{ 
    bool ImportRoute(Stream inputStream, string fileName)
    { code here etc etc } 
    List<Route> GetAllRoutes();
    List<Route> GetAllRoutesForDate(DateTime from, DateTime to);
    void DeleteRoute(string routeName);
    void DeleteAllRoutes();

}

You coudl also change the word interface to class if its a class you wish instead.

answered Jun 16, 2012 at 10:00

nyxthulhu

9,8029 gold badges60 silver badges92 bronze badges

Collectives™ on Stack Overflow

How to create an instance of an Interface(access to Interface)

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