在类构造函数中使用泛型类型

Question

I have an Interface and an Abstract class with its derived one:

  public interface IIndicator<TInput, TOutput> { } 

  public abstract class Indicator<TInput, TOutput> : IIndicator<TInput, TOutput> {

    public abstract TOutput Calculate(TInput input);

  }

  public class MyIndicator : Indicator<Decimal, Decimal?> {

    public MyIndicator(IEnumerable<Decimal> inputs) {
      // Code using base.Calculate and inputs
    }

    public MyIndicator(IEnumerable<Decimal> inputs, Func<TMapper, Decimal> mapper) {

      // Code using base.Calculate, inputs and mapper 

    } 

    public override TOutput Calculate(TInput input) {
      // Implementation of Calculate
    }

  }

The problem is that TMapper is not defined in the contructor:

public MyIndicator(IEnumerable<Decimal> inputs, Func<TMapper, Decimal> mapper, Int32 period)

I would like to use MyIndicator as:

MyIndicator indicator = new MyIndicator(inputs, x => x.Id)

Instead of:

MyIndicator<MyClass> indicator = new MyIndicator<MyClass>(inputs, x => x.Id)

Where MyClass would be something like:

public class MyClass { 
  public Int32 Id { get; set; }
}

Is this possible?

Answer 1

Use a factory method instead eg

public static MyIndicator Create<TMapper>(IEnumerable<decimal> inputs, Func<TMapper, decimal> mapper, int period)
{
    var indicator = new Indicator(inputs);
    // do stuff with your mapper / period
    return indicator;
}