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Question

I have an inheritance problem.
I started with something similar to:

public class POpt
{
...
    private decimal profit;
    public decimal Profit
    {
        get { return profit; }
    }
...
}

public class Opt
{
...
    private List<POpt> pases;

    public int NumPasesPositivos()
    {
        return pases.Where(o => o.Profit > 0).Count();
    }
...     
}

And it works .. I can call NumPasesPositivos() and get the number of pases with positive profit in the List pases.

Right now, I have to write two similar classes like Popt and Opt... and use inheritance:

abstract public class P
{
...
...
}

public class POpt: P
{
...
    private decimal profit;
    public decimal Profit
    {
        get { return profit; }
    }
...
}

public class PBt: P
{
...
...
}

And also:

abstract public class T
{
...
    private List<P> pases;
...     
}

public class Opt: T
{
...
    public int NumPasesPositivos()
    {
        return pases.Where(o => o.Profit > 0).Count();
    }
...     
}

public class Bt:T
{
...
...     
}

Now, the list in the class T pases, can be a POpt or PBt clases list. Problem is that right now, I can´t use NumPasesPositivos because pases can be POpt or PBt and Profit its not defined in PBt, and I cant cast
pases in OPt to someting like (List<POpt>pases).Where(o => o.Profit > 0).Count() ....Im not sure how to solve the problem nor how to rewrite the classes...

Answer 1

You can use the OfType extension method and restrict to types that can be cast to POpt .

public int NumPasesPositivos()
{
    return pases.OfType<POpt>().Where(o => o.Profit > 0).Count();
}