Inheritance and Collections

[rodrick]

I have a base class called Vehicle and a collection of Vehicles called VehicleCollection.

I created another class called Truck derived from the base class Vehicle. The Truck class has an extra property called Trailer.

Can I create an instance of the VehicleCollection and add a Truck object to the collection?
If so how can I access the property Trailer? myVehicle[0].Trailer doesn't work.

Any advice on how to get round this would be great.

Thanks
R

[DeadEyes]

If your collection stores items as type object you can
Truck t = (Truck)myVehicle[0];
and checking that it is of type Truck.
Given that this looks more like a learning example the solution probably lies in creating an Interface IVehicle.

[hellswraith]

Doing this is a more safe way to do it so you don't accidently get a Car trying to be cast into a Truck:

Truck t = myVehicle[0] as Truck;
if(t != null)
{
   t.Trailer = new Trailer();
}