157 recommendations for writing high-quality code to improve C # programs--Recommendation 111: Avoid bidirectional coupling

Recommendation 111: Avoid bidirectional coupling

Bidirectional coupling refers to the mutual reference between two types. The following code is a typical bidirectional coupling:

    class A    {        private  b b;          Public void MethodA ()        {            b.methodb ();        }    }     class B    {        private  a A;          Public void MethodB ()        {            A.methoda ();        }    }

Two-way coupling under the same project, there will not be too many problems, only the design problems. However, if the two classes are in a different project, you must consider decoupling, because. NET does not allow cross-referencing between projects. If you try two items with each other, an error will appear.

The common decoupling method is to extract an interface. If the type A and B are in two projects, then the extracted interface should be placed in the new project, and then the two projects where A and B are located will refer to the project where the interface is located respectively.

The decoupled code looks like this:

    Interface Isample    {        void  MethodA ();    }     class A:isample    {        private  b b;          Public void MethodA ()        {            b.methodb ();        }    }     class B    {        isample A;          Public void MethodB ()        {            A.methoda ();        }    }

Interface Isample regulates the behavior of type A, while having type a inherit from Isample. In type B, we program the interface, that is, field A in B is no longer a type, but instead modifies it to the isample type.

In general, there should be no bidirectional coupling between types, and refactoring should be considered if such a situation arises. There are third-party frameworks that support decoupling projects, such as unity and Spring.net in the Microsoft Enterprise Library. In the actual coding, consider using these frameworks to design our projects.

Turn from: 157 recommendations for writing high-quality code to improve C # programs Minjia

157 recommendations for writing high-quality code to improve C # programs--Recommendation 111: Avoid bidirectional coupling