Question

What is the difference between these terms, can you give please small examples?

Answer 1

Aggregation: From http://en.wikipedia.org/wiki/Aggregate_pattern

In Design Patterns, an aggregate is
not a design pattern but rather refers
to an object such as a list, vector,
or generator which provides an
interface for creating iterators.

Meaning in short on elements contains 0 or more other elements of another type.

public class MyAggregation 
{   
   protected List<MyAggregates> aggregates = new List<MyAggregates>();

   public void add( MyAggregate element )
   {
        aggregates.Add( element );    
   }
}

Delegate: From http://en.wikipedia.org/wiki/Delegation_pattern

In software engineering, the
delegation pattern is a design pattern
in object-oriented programming where
an object, instead of performing one
of its stated tasks, delegates that
task to an associated helper object

Meaning that some class uses another object to do something.

public interface IExceptionHandler
{
    void handle( string filename );
}

public class FileDeleteExceptionHandler : IExceptionHandler
{
   public void handle( string filename )
   {
      File.Remove( filename );
   }
}


public class MyExceptionHandler
{
    protected IExceptionHandler exceptionHandler;

    public MyExceptionHandler( IExceptionHandler theHandler )
    {
       this.exceptionHandler = theHandler;
    }

    public void handleException( string filename )
    {
       excpetionHandler.handle( filename );
    }
}

Or in C# delegation can just refer to a delegate function, see http://msdn.microsoft.com/de-de/library/900fyy8e%28VS.80%29.aspx

Consultation I know nothing off, sorry

hth

Mario

Note: I did not actually compile the code above.