c# - Cast générique avec un type dérivé de générique avec un type de parent - Stack Overflow

I have a base class:

public abstract class InputParserBase<TInputData> : ServerComponentBase
        where TInputData : SolverDataBase
    {
        public abstract TInputData Parse(ClientInputData task);               
    }

and a child:

public class BinomTaskParser : InputParserBase<BinomTaskData>
    {

        public override BinomTaskData Parse(ClientInputData inputData)
        {//Some stuff
        }
    }

BinomTaskData is inherited from SolverDataBase

My second class is in another assembley and i load it in runtime. And the thing is that i can have different childs with another types, derived from SolverDataBase. I want to load them and store like this:

var result = new List<InputParserBase<SolverDataBase>>();
var parser = (InputParserBase<SolverDataBase>)AssembleyHelper.CreateInstance(typePair, null);
result.Add(parser);

But get a cast exception. What am i doing wrong and how can i implement this?

Classes are invariant so the cast is invalid. You could create an interface:

public interface IInputParser<out T> where T : SolverDataBase
{
    T Parse(ClientInputData);
}

and implement it in the base class or in each subclass:

public abstract class InputParserBase<TInputData> : ServerComponentBase, IInputParser<TInputData>
        where TInputData : SolverDataBase
{
    public abstract TInputData Parse(ClientInputData task);
}

then you can create a list like:

var result = new List<IInputParser<SolverDataBase>>();
var parser = (IInputParser<SolverDataBase>)AssembleyHelper.CreateInstance(typePair, null);
result.Add(parser);

I have a base class:

public abstract class InputParserBase<TInputData> : ServerComponentBase
        where TInputData : SolverDataBase
    {
        public abstract TInputData Parse(ClientInputData task);               
    }

and a child:

public class BinomTaskParser : InputParserBase<BinomTaskData>
    {

        public override BinomTaskData Parse(ClientInputData inputData)
        {//Some stuff
        }
    }

BinomTaskData is inherited from SolverDataBase

My second class is in another assembley and i load it in runtime. And the thing is that i can have different childs with another types, derived from SolverDataBase. I want to load them and store like this:

var result = new List<InputParserBase<SolverDataBase>>();
var parser = (InputParserBase<SolverDataBase>)AssembleyHelper.CreateInstance(typePair, null);
result.Add(parser);

But get a cast exception. What am i doing wrong and how can i implement this?

Classes are invariant so the cast is invalid. You could create an interface:

public interface IInputParser<out T> where T : SolverDataBase
{
    T Parse(ClientInputData);
}

and implement it in the base class or in each subclass:

public abstract class InputParserBase<TInputData> : ServerComponentBase, IInputParser<TInputData>
        where TInputData : SolverDataBase
{
    public abstract TInputData Parse(ClientInputData task);
}

then you can create a list like:

var result = new List<IInputParser<SolverDataBase>>();
var parser = (IInputParser<SolverDataBase>)AssembleyHelper.CreateInstance(typePair, null);
result.Add(parser);

Source