Declare IDisposable for the class or interface?

Question

Starting from the follwing situation:

public interface ISample
{
}

public class SampleA : ISample
{
   // has some (unmanaged) resources that needs to be di         


        

Answer 1

Following the Inteface Segregation Principle of SOLID if you add the IDisposable to the interface you are giving methods to clients that are not interested in so you should add it to A.

Apart from that, an interface is never disposable because disposability is something related with the concrete implementation of the interface, never with the interface itself.

Any interface can be potentially implemented with or without elements that need to be disposed.