How much do you pay per line of code?

http://www.yegor256.com/2014/04/11/cost-of-loc.html

Service Locator vs. Dependency Injection

Includes C# code examples to compare two pattern.
https://software2cents.wordpress.com/2013/03/30/service-locator-vs-dependency-injection/

60 Problem Solving Strategies

http://java.dzone.com/articles/60-problem-solving-strategies

What is difference between Service Locator and Dependency Injection?

From Martin Fowler
http://martinfowler.com/articles/injection.html#ServiceLocatorVsDependencyInjection

From Stackoverflow
http://stackoverflow.com/questions/1557781/whats-the-difference-between-the-dependency-injection-and-service-locator-patte

Will try to write home-made  Service Locator first to see what happen.
If any problem, will try DI containers, such Autofac

Why readonly in C#?

Make summary form following post:
http://stackoverflow.com/questions/277010/what-are-the-benefits-to-marking-a-field-as-readonly-in-c

1. Improve readability: tell how to not use in other way.
2. Nothing to do with performance
3. Immutable data structures in threading