SOLID principle

Chanmingman's Blog

There is a lot of debate on SOLID principle.

The video Applying SOLID Principles in .NET   ( is worth to watch.

I like the last slide Consideration


As he mentioned.

1. Someone just over engineering using the term SOLID

2. How readable for your Dependency Injection if you have large set of object.

3. When talking about maintainable, before SOLID is 50 lines of code, after SOLID is 230 lines of code previewing the same functionality. So you think 50 lines of code is easier to maintain or 230?

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SOLID design principles in .NET: the Open-Closed Principle

Exercises in .NET with Andras Nemes


In the previous post we talked about the letter ‘S’ in SOLID, i.e. the Single Responsibility Principle. Now it’s time to move to the letter ‘O’ which stands for the Open-Closed Principle (OCP). OCP states that classes should be open for extension and closed for modification. You should be able to add new features and extend a class without changing its internal behaviour. You can always add new behaviour to a class in the future. At the same time you should not have to recompile your application just to make room for new things. The main goal of the principle is to avoid breaking changes in an existing class as it can introduce bugs and errors in other parts of your application.

How is this even possible? The key to success is identifying the areas in your domain that are likely to change and programming to abstractions. Separate out…

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