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Class Interface

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Class Interface

Feb 11th, 2009

Hi I am slightly confused about interfaces for an inheritance structure. Firstly can anyone explain there purpose, secondly can anyone demonstrate there use.

I have created an application that uses reflection to dynamically instantiate classes and invoke methods within those classes. During research for this app I cam accross interfaces but was lost at there purpose and the syntax of there use.

I would be greatful if anyone can help. Thanks

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DrLod

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Re: Class Interface

Feb 12th, 2009

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Originally Posted by FallenPaladin

Hi I am slightly confused about interfaces for an inheritance structure. Firstly can anyone explain there purpose, secondly can anyone demonstrate there use.

I have created an application that uses reflection to dynamically instantiate classes and invoke methods within those classes. During research for this app I cam accross interfaces but was lost at there purpose and the syntax of there use.

I would be greatful if anyone can help. Thanks

You can use interfaces to structure up your programming when using polymorphism and to pass objects that are different but who all have some methods that are defined in the interface.

Example: http://www.codersource.net/csharp_tu...interface.html

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Re: Class Interface

Feb 12th, 2009

Just to add to this:

If you're using reflection frequently because you have several classes that have the same method, you could consider casting those objects up to a defined interface. Say you have two classes, ClassA and ClassB. Both classes have a method called Run(), which you've defined in an interface called IRunnable:

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
public interface IRunnable
{
     public void Run();
}
 
ClassA a = new ClassA();
ClassB b = new ClassB();
 
//casting up to IRunnable
IRunnable aR = (IRunnable)a;
IRunnable bR = (IRunnable)b;
 
//you could then pass these IRunnables to any method that takes an IRunnable as a parameter, for instance.
 
private static void MakeRun(IRunnable r)
{
     r.Run();
}
 
MakeRun(aR);
MakeRun(bR);
public interface IRunnable
{
     public void Run();
}

ClassA a = new ClassA();
ClassB b = new ClassB();

//casting up to IRunnable
IRunnable aR = (IRunnable)a;
IRunnable bR = (IRunnable)b;

//you could then pass these IRunnables to any method that takes an IRunnable as a parameter, for instance.

private static void MakeRun(IRunnable r)
{
     r.Run();
}

MakeRun(aR);
MakeRun(bR);

...This is a really simple example, but I hope you get a good idea. You can do similar things with Interfaces that you can do with Reflection. I think it's cleaner to use Interfaces because you then have type-safety when executing those methods when returning values and inputting parameters.

Alex Cavnar, aka alc6379