处理具有潜在空子类的复杂类的良好设计模式是什么？

Question

I am using Entity Framework Model First to create a data access layer. In my MVC project I am using this DAL to retrieve a complex object from my DB.

var street2 = Person.Address.Street2;

What I am trying to determine is what pattern or process I should be using to handle potential situations where Street2 or even Address doesn't have a record in the DB.

I know I could test for null objects at the point where I am using them but I was wondering if there is a pattern or method that would remove the need to do that at such a fine grained level. ie

if(Person.Address!=null && Person.Address.Street2!=null)
{
var street2 = Person.Address.Street2;
}

Until we get a Safe Navigation Operator is there another good pattern to use?

Would it make sense to create a getter in the classes to check for null objects and if there is create a new empty object and return that?

Am I making this more complex then it needs to be?

Any thoughts on AutoMapper and it's null substitution?

Answer 1

No. That's the way you've to do it. You've to do it the way you're doing.

However use short circuit in your if conditions to increase performance

Answer 2

您可以创建对象验证器并使用Decorator模式进行更新，这样，您仍然必须手动在逻辑需要的地方检查是否为空。