C＃实体框架更好的功能或模型中的计算属性？

Question

Hello I'm writing a little C# web app using asp.net core 1.1 MVC with EF (code first)

I want to know what is the best engineering choice. Let's assume that I have a class and I need to calculate something using one or more related properties; let's make an example:

class A
{
    public virtual int Id { get; set; }
    public virtual Collection<B> Bs { get; set; }    

    public int GetMaxB()
    {
        return Bs.Max( b => b.Num ); /*simple example, can be more complex */
    }
}

class B
{    
   public virtual int Id { get; set; }
   public virtual int Num { get; set; } 
}

So, for GetMaxB() (let's think about a more complex function, not only one line) what is the best option?

• a function in the model class
• a generated (NotMapped) property in the model class
• a function in controller
• other

Answer 1

您的逻辑可以是VM的一部分，您可能不希望将其与Model混合使用，而Model应该是具有属性的纯类。

Answer 2

Depends upon situations and nature of property.

A calculated property like DiscountValue (which depend few other properties) be part of Model class.

If use of a GetMaxB() is less frequent then it can be a function in Model.

If GetMaxB() is only reason for which collection class is used in Class A, then you can think separate out provided use is not frequent.