Dependency Injection?

Question

User2118885047 posted

Hi,

I have read some articles over DI, but not clear still. Can any one explain me in SHORT. WITH EXAMPLE PLEASE

Answer 1

User-821857111 posted

See if this article is clearer than the others you have read: http://www.mikesdotnetting.com/Article/117/Dependency-Injection-and-Inversion-of-Control-with-ASP.NET-MVC

Answer 2

User2118885047 posted

Thanks Mike,

I understand what is DI, but

what is difference between calling a static method (i think its loosely coupled, all our Db coding will be in this method).

AND

DI?

More or less, i see both are same right?

Answer 3

User-989998403 posted

DI is primarily about reducing the dependencies of your code and writing more testable code.  For example, you reference having your DB code in a static class.  Well the class using that static class is now tightly coupled to it.  You are unable to write unit tests without hitting the database, generally unit tests should have no external dependencies.

If you abstract the data access layer out and inject an interface, you can switch out concrete implementations with fake or mock impelementations. Thus allowing your code to be easily testable. 

Hope that helps a little.

Answer 4

User2118885047 posted

Yes exactly I as thinking of this. 

As I am new to MVC, I need to do some practice tests, to make this understand perfectly. Thanks.