.NetExtension methodsFrameworksTalks

October 19. Talk. “Do’s and don’t in implementing and applying extension methods”

SDC Conference, Papendal, Arnhem (www.sdc.nl)

Next week the annual SDC conference will take place at Papendal, Arnhem. As usual the organising SDN community has put together a long list of international appraised speakers, and challenging subjects on the matter of software development and software architecture.


A bit to my surprise, this year I was invited to do 3 talks, with very different subjects: Silverlight and code generation, smart use cases in service oriented projects, and .NET extension methods, which is a very small subject compared to the other two, but still a nice way of getting to talk about OCP, LSP and the new construct. Following the article I wrote for .NET Magazine recently. Should be interesting.

Extension methods

The SDC website refers to my extension methods talk as follows:

To implement the operators that make up the language feature LINQ Microsoft’s .NET Framework designers had to extend existing types with new features. To be able to do this without touching the existing classes, they introduced another language feature in .NET 3.5 – extension methods.

During this talk Sander Hoogendoorn will demonstrate the use of extension methods with simple examples, but he will also investigate the way these extension methods are handled. For instance, do extension methods break the Open Closed Principle (OCP)? What is the open closed principle anyway? Can I use extension methods to break into existing classes, either in our own framework or in someone else’s frameworks (Microsoft or open source)? What is allowed in extension methods, and how do they work?

Read more: Sander at SDC 2009.