Alternative to the use of new when implementing methods that return this in child classes

Question

Taking the example of the following code:

public class Pai
{
    protected string PropriedadeA { get; set; }
    public Pai Metodo1(int valor)
    {
        //Vários procedimentos feitos aqui
        PropriedadeA = "Resultado do tratamento";
        return this;
    }
}

public class Filha : Pai
{
    public new Filha Metodo1(int valor)
    {
        base.Metodo1(valor);
        return this;
    }
}

Is there any alternative to avoid rewriting the method in the class Filha?

This arose from the need to implement the Fluent Interface in several classes. These classes inherit the functionalities of the others and add new.

So that the Fluent Interface work the methods have to return the class Filha and not the class Pai.

public interface IDataConfiguration<TResponse>
{
    TResponse GetData();
    Task<TResponse> GetDataAsync();
}

public interface IDataVideoConfiguration<TResponse> : IDataConfiguration<TResponse>
{
    IDataVideoConfiguration<TResponse> VideoName(string videoName);
    IDataVideoConfiguration<TResponse> CosmoId(string cosmoId);
    IDataVideoConfiguration<TResponse> I_GuideId(string iGuideId);
}

public interface IDataVideoImagesConfiguration<TResponse>
{
    IDataVideoImagesConfiguration<TResponse> VideoName(string videoName);
    IDataVideoImagesConfiguration<TResponse> CosmoId(string cosmoId);
    IDataVideoImagesConfiguration<TResponse> I_GuideId(string iGuideId);

    IDataVideoImagesConfiguration<TResponse> ImageFormatId(string formatId);
    IDataVideoImagesConfiguration<TResponse> ImageSize(string imageSize);
    IDataVideoImagesConfiguration<TResponse> ImageSort(string imageSort);
    TResponse GetData(int count = 0, int offset = 0);
    Task<TResponse> GetDataAsync(int count = 0, int offset = 0);
}  

The class Pai implements IDataVideoConfiguration<TResponse> the problem arises when implementing the class Filha inheriting from Pai:

public class Filha<TResponse> : Pai<TResponse>, IDataVideoImagesConfiguration<TResponse>

Answer 1

I will say that I do not know if it solves the problem but at least it helps to have ideas:

using System.Console;

public class Program {
    public static void Main() {
        var pai = new Pai();
        WriteLine(pai.Metodo1(1).GetType());
        var filha = new Filha();
        WriteLine(filha.Metodo1(1).GetType());
        filha.PropriedadeB = "xxx";
        WriteLine(filha.Metodo1(1).GetType());
        var temp = filha.Metodo1(1);
        WriteLine(temp.PropriedadeB);
    }
}

public class Pai : Pai<Pai> { }

public class Pai<T> where T : Pai<T> {
    protected string PropriedadeA { get; set; }
    public T Metodo1(int valor) {
        //Vários procedimentos feitos aqui
        PropriedadeA = "Resultado do tratamento";
        return (T)this;
    }
}

public class Filha : Pai<Filha> {
    public string PropriedadeB { get; set; }
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.

Surely it has limitations but it already solves something.

But also prepare to have to take the trouble of reproducing methods unnecessarily. Sometimes to simplify the life of the consumer greatly increases the work of the supplier.

Answer 2

I took the following test:

using System;

public class Pai
{
    protected string PropriedadeA { get; set; }
    public Pai Metodo1(int valor)
    {
        //Vários procedimentos feitos aqui
        PropriedadeA = "Resultado do tratamento";
        return this;
    }
}

public class Filha : Pai
{

}

public class Program
{
    public static void Main()
    {
        Console.WriteLine("Hello World");
        var filha = new Filha().Metodo1(1);
        Console.WriteLine(filha.GetType());
    }
}

The guy returned was Filha. There is no need to reintroduce the method.