c# List of derived class

Question

I'm developing a C# WinForm application for work, but I'm stuck and I don't know which is the best way to proceed on. Here's a snippet of code

class Block()
{
   // generic Block properties
}

class ABlock() : Block
{
    // specific ABlock stuff
}

class BBlock() : Block
{
    // specific BBlock stuff
}


abstract class Algorithm()
{
   // generic Algorithm properties
   abstract List<Block> BlockList // ??
}

class AAlgorithm() : Algorithm
{
    // specific AAlgorithm stuff
    List<ABlock> BlockList // ??
}

class BAlgorithm() : Algorithm
{
    // specific BAlgorithm stuff
    List<ABlock> BlockList // ??
}

I think the situation is pretty simple: every derived class of Algorithm has it's own derived class of Block , but I want to make it generic and accessible from List<Block> BlockList in asbtract class Algorithm . I think that it's a common situation and I'm sure there is a solution.

Thanks in advance

Answer 1

I might be missing something, but couldn't you make it an abstract property?

abstract class Algorithm()
{
   abstract List<Block> BlockList { get; }
}

... then when, writing a class that derives from Algorithm, it won't compile unless the BlockList.get is implemented:

public class AlgorithmA : Algorithm
{
    public override List<Block> Blocks
    {
        get
        {
            return new List<Block> { new ABlock(), new ABlock() };
        }
    }
}

About the only blemish is that, if code within AlgorithmA wants to use the Blocks property, it might need to cast as (ABlock).