Lets take a look at this step-by-step.
1: You have an interface which defines your code contract defined like so:
public interface IBase
{
void Refresh();
}
2: You have a base class which implements your interface. (you will notice that the implementation for refresh is virtual
. This allows you to override this method in derived classes).
class Base : IBase
{
public virtual void Refresh()
{
//Implementation
}
}
3: You have a super class which derives from Base. (you will notice that the derived class does not need to explicitly implement IBase
as it's done at a lower level. I'll show you that you can test the integrity of this).
class Child : Base
{
public override void Refresh()
{
base.Refresh(); //You can call this here if you need to perform the super objects Refresh() before yor own.
//Add your implementation here.
}
}
At this point you might be thinking; "Ok, well then how is Child implementing IBase?". The answer is that it is implemented indirectly through Base, and because Child
inherits Base
, it also gets the implementation for IBase
.
Therefore if you were to write:
IBase instance = new Child();
This is perfectly legal because essentially, Child
derives from IBase
indirectly.
If you wanted to test this, you can do this in your code:
bool canAssign = typeof(IBase).IsAssignableFrom(typeof(Child));
//canAssign should be true as Child can be assigned from IBase.