Interfaces? 2

[pererm]

Hi. I´m looking around VisualStudio.NET, Visual C++.NET really, and i find out the concept "interface" like a new element of code inside on project. I think that this seem to be like a type of class that allow other classes use a way of relation each other, but really i don´t understand the real meaning of "interface". Can someone coment more axactly, which is their function inside the code? Thanks. PERE

 

[mingis]

I'm not sure about .NET, but in COM Interface class means a certain base class with virtual methods, which only are exported to external applications. Implementation part of these methods are internal classes derived from that interface class and unknown for external user.

 

[pererm]

Thanks mingis, only one thing more, i understand you can create a class derived of this internal inteface class, and add it to your project. It´s that right? Thanks, PERE

 

[timmay3141]

Yes, you can derive one of your classes from this interface just as you could derive it from any other class.

 

[pererm]

OK Thanks, timmay3141. It´s more useful for me. But if is possible can u tell me in what kind of situations is more indicated use an interface class instead a normal class. Thanks. PERE

 

[mingis]

Purpose of interfaces is distinguishing different realisations processing different things from common calling conventions to all these implementations. Let say, drivers of hard disk and diskette internally are different, but have common calling parameters (i/o buffer, tracks, heads, etc.) and common interface methods (read(), write(), ...).