dependency-inversion

问题 Just a thought and a question to the Stack Overflow and Microsoft Development Community about the OO software design principles called SOLID. What is the difference between the Liskov Substitution Principle and the Dependency Inversion Principle please ? I have thought about this for a while and I'm not sure of the difference. Please could you let me know ? Any thoughts / feedback very welcome. 回答1: Liskov's substitution Principle states the following: A class should be directly substitutable

问题 The Situation: I have three classes: Society, Father and Son. The Society has a list of Fathers. Each Father has one son. It is necessary in this application that each Father knows who his Son is and vice-versa each Son knows who his Father is. I have used direct cross referencing by assigning the Father as a property of the Son, and the Son as a property of the Father class, as below: public class Society : ISociety { public List<IFather> Fathers {get; set;} } public class Father : IFather {

问题 The way we can implement an Interface to an es6 class is pretty straightforward: interface IDog { bark(): void } class Dog implements IDog { bark(): void { } } The question is: how to implement the same interface to this "class": const Dog = function() { } Dog.prototype.bark = function() { } I tried defining the type of Dog as IDog: const Dog: IDog . Didn't work. So, I need it to implement Dependency Inversion and I can't figure out how to do this with es5 classes. I saw that Classical

问题 I have a framework Whiteboard that encapsulates my business logic. I'm trying to keep my dependencies inverted and decoupled, so since Whiteboard depends on a repository, it declares a protocol WhiteboardRepository , and it expects clients that link against Whiteboard to supply an implementation of WhiteboardRepository . You can see this in the screen shot below. Note also the WhiteboardTests group, which includes a WhiteboardRepositoryTests class along with a WhiteboardRepositoryFake and its

问题 I was reading Wikipedia's definition of Dependency inversion principle, and it uses two terms High-level modules and low-level modules , which I wasn't able to figure out. What are they and what does Dependency inversion principle have to do with them? 回答1: The definition of those are given in the introductory sentence: high level: policy setting low level: dependency modules. In laymen's terms: high level modules depend on low level modules, but shouldn't depend on their implementation. This

问题 I was reading Wikipedia's definition of Dependency inversion principle, and it uses two terms High-level modules and low-level modules , which I wasn't able to figure out. What are they and what does Dependency inversion principle have to do with them? 回答1: The definition of those are given in the introductory sentence: high level: policy setting low level: dependency modules. In laymen's terms: high level modules depend on low level modules, but shouldn't depend on their implementation. This

问题 I'm currently thinking of "How to design an OSGi component so that it's easy to write tests for it with frameworks like jUnit and Mockito" . Mocking inter-bundle-dependencies is quite easy since OSGi strengthens the DIP (Dependency Inversion Principle) and injector-methods (e.g. setter) usually exist. But what about bundle internal dependencies? For example look at this case. Now I want to bring it into an OSGi context... Image we want to provide any kind of network protocol as a declarative

问题 As per this Wikipedia article: Implementing Dependency Inversion Principle can be done in two ways: Having an abstraction of a low level component in a separate package upon which both high level and low level components depend. Having the abstraction of the low level component reside in the same package of the high level component. The following illustration depicts the dependencies before and after DIP using the two approaches: Before DIP: The repository resides in a separate maven module

问题 " Code to interfaces " is considered good practice. Such code is easy to unit test and enables loose coupling. Users only know the interfaces and the onus of wiring concrete objects is upon the top-most level (this can be done in some init code or with the help of frameworks). My question is about following the practice of code to interfaces : does it imply that a concrete class can never declare any public method which is not present in its interface? Otherwise, it will force users to depend

问题 I am using .NET Core dependency injection, but when I am trying to get the service in another class, I am getting the 'IServiceProvider.GetService(Type)' cannot be used with type arguments' error. What does this error means? I understand that a generic type argument is something like this: GenericInterface<>, and the GetService method does not take the GenericInterface<> as an argument. Why am I getting this error and how do I solve it? The interface public interface IService { void Process()