Do an OA project from scratch (v) interface-oriented programming and relationship referencing between tiers

UI The previous article we have led you to build a very simple three-tier architecture, and in accordance with the Order of construction (entity class library, data access, business logic, UI, about the order of building three layers, there is no unified statement, but I am accustomed to bottom building). Once again picture (1-1) let's recall.

Figure 1-1

(i) Add a reference relationship

We are now going to reference relationships between the three tiers of each class library. Follow the previous article on the three floor to make a reference relationship. The data access layer references the Entity class library, the business logic layer references the data access, and the UI layer refers to the business logic layer, so the entity class library is referenced between the three tiers. Again, the Entity class Library is not a hierarchy in layer three, and the entity class library is nothing more than a data container that is transferred in layer three. I'll use the modeling tool in VS to draw the reference relationship first.

This is a sample diagram of our citation relationship, and for our vs project, adding a reference is simple. Let's take a look at how to add a reference.

Data access referencing entity class libraries

business Logic Layer Reference

Above is the reference relationship of the UI layer

Do an OA project from scratch (v) interface-oriented programming and relationship referencing between tiers