c# - Refactoring code in using specification pattern for business rules -

I Specification pattern to implement business rules in N-Layerd DDD I used to use the application I also used the CQRS pattern in my application layer . So I have defined the following in the interface my domain :

  public interface ISPPfication & lt; T & gt; {Expression & lt; Funk & lt; T, bool & gt; & Gt; Preddict {Received; } Boolean Assurified By (T Entity); }  

Anything else specificity which is the big order explanation: ISPsification and Special Order Explanation: ISpecification & lt; Order & gt; . .

I have used the following handler to process my orders:

  Public class commanding process: CommandMandHandler  

I think that violates the law of method , violates ,

• Do not ask for the theory, because it Satisfaction result from br asks order and then decides to do somethings.

• Open / Closed Principle, because if I want to add another specification, I have to change my command handler .

  How can I repeat my code to prevent this violation?

I would not say that it violates principles.

1. Principle / Strong>

   Your code follows this principle because you define handles and your "logic" and "data" are kept in the same method.

   This can be violated if your does some work argument tells something to special order clarity .

2. Open / Closed Principle

   Your code adheres to this principle because you have ICommandHandler & lt; T & gt; The interface should not be changed if you want to add another specification

   If you add one more specification then it can be violated ICommandHandler & lt; T & gt; Change the interface is necessary.

Follow the Dependency Inversion Principle . I suggest you use all your specifications (like BigOrderSpecification , SpecialOrderSpecification ) Inject through the constructor.