将模型的检查功能放在何处（asp.net mvc5）

Question

i know the model should not have any logic , but i don't know where is the good place to put the checking or the update function for a particular model

ex.

public class GuestBook
    {

        public int money { get; set; }
        [Required]
        public string name { get; set; }
        [Required]
        public string email { get; set; }
        public DateTime content { get; set; }
        public bool rich()
        {
            if (this.money <3000)
                return false;
            else
            return true;
        }
        public void earn(GuestBook b)
        {
            this.money += b.money;
        }
    }

the function rich() and earn() is only use for this module(GuestBook) if i didn't put it in this module , then where i should put?

Answer 1

Following good OOP design principles, the only way to really protect your classes' invariants (and not have a maintainability nightmare) is by not allowing them to be changed by anyone other than the class. Typically this is done by NOT exposing public setter methods ( public auto properties are evil ), making your fields readonly (wherever possible), and initializing them from the constructor.

The whole point of having classes is to group data with behavior. A simple data structure containing ints and strings is not a class in the OOP sense, it's just a struct.

In some cases you are stuck with an even more evil ORM that FORCES you to make all properties public. This is not an issue with Entity Framework (and some others too) though, EF can magically reflect in and access private setters if needed, you just gotta make sure there's also a private default constructor.

Answer 2

According to your class rich method is validating and earn method is applying business logic. You can create AdditionalMetadataAttribute for rich method logic that can fire on ModelState.IsValid and for earn method you need to create BO class that apply your all business logic. here a link for AdditionalMetadataAttribute