C# Using Activator.CreateInstance

Question

I asked a question yesterday regarding using either reflection or Strategy Pattern for dynamically calling methods.

However, since then I have decided to change the

Answer 1

I suggest you give your factory implementation a method RegisterImplementation. So every new class is just a call to that method and you are not changing your factories code.

UPDATE:
What I mean is something like this:

Create an interface that defines a calculation. According to your code, you already did this. For the sake of being complete, I am going to use the following interface in the rest of my answer:

public interface ICalculation
{
    void Initialize(string originalData);
    void DoWork();
}

Your factory will look something like this:

public class CalculationFactory
{
    private readonly Dictionary> _calculations = 
                        new Dictionary>();

    public void RegisterCalculation(string method)
        where T : ICalculation, new()
    {
        _calculations.Add(method, originalData =>
                                  {
                                      var calculation = new T();
                                      calculation.Initialize(originalData);
                                      return calculation;
                                  });
    }

    public ICalculation CreateInstance(string method, string originalData)
    {
        return _calculations[method](originalData);
    }
}

This simple factory class is lacking error checking for the reason of simplicity.

UPDATE 2:
You would initialize it like this somewhere in your applications initialization routine:

CalculationFactory _factory = new CalculationFactory();

public void RegisterCalculations()
{
    _factory.RegisterCalculation("Pivot");
    _factory.RegisterCalculation("GroupBy");
    _factory.RegisterCalculation("Standard deviation");
    _factory.RegisterCalculation("% phospho PRAS Protein");
    _factory.RegisterCalculation("AveragePPPperTreatment");
    _factory.RegisterCalculation("AvgPPPNControl");
    _factory.RegisterCalculation("PercentageInhibition");
}