如何在工厂方法设计模式中添加不同的参数集以实现正确的设计

Question

I have a scenario where two different classes have many properties and one different property. How do I use factory design pattern or should I not use it? Internal private methods of these sub classes make use of these properties.

public class RunsValidator  
{  
     //Few common properties  
     public int DataSegmentID { get; set; }  
     public int AttributeOffset { get; set; }  
}

public class ProductAttributeRunValidator : RunsValidator  
{

    public ProductAttributeRunValidator(string productNames)
    {
       this.ProdNames = productNames;
    }
}

public class CategoryAttributeRunValidator : RunsValidator  
{  

     public CategoryAttributeRunValidator(int orgIDs) : base()  
          {  
            this.totalOrgIDs = orgIDs;  
          }  

}  

//Factory implementation

public class RunAttributeFactory  
{     

    public static RunsValidator GetRunValidator(string type, string productNames, int orgIds)  
     {  
      RunsValidator runValidator = null;  
      if(type == "Product")  
      {   
           runValidator = new ProductAttributeRunValidator(productNames);  
      }  
      else if (type == "Category")  
      {  
           runValidator = new CategoryAttributeRunValidator(orgIds);  
      }  
      else  
      {  
          runValidator = null;  
      }  
      return runValidator;  
    }  
}

In the client code, I have access to variables that should be sent as parameters (productNames, orgIds and type) to the Factory method. I would like to access the returned runValidator in many places in the client code as it needs to be set only once based on the type.

Which is the best way to achieve this?

Answer 1

Considering that the client will have to know the type of the output to know what parameters to pass in, and that you have no re-usable code between the two types, I see no value from a "generic" factory pattern here. I would either have two factories (if you even need a factory for either type), or let the client call the type constructor directly.