What should I consider when choosing a dependency injection framework for .NET

Question

see also Which C#/.NET Dependency Injection frameworks are worth looking into?

There are now many dependency injection frameworks to

Answer 1

FYI, just this morning I came across an interesting comparison between all the .NET IoC containers here:

http://elegantcode.com/2009/01/07/ioc-libraries-compared/

A handful of questions:

1. How much mainstream support do you need? Spring is probably the biggest one out there. Everyone has used it or has heard of it by now, so lots of info. It also probably has the largest number of features, but that means there's just more to learn. A smaller container like Autofac might be nice, but you might come across an issue you won't find help on.
2. Are you handy with XML configuration? Every IoC container relies on configuration and setup of some sort. Spring and Unity are XML heavy.
3. Is this a permanent choice? If you are at one of those places where you only get one shot at a choice, it won't matter. But, if you ever want to choose another solution down the road, you probably don't want an IoC that requires you to attribute your classes (sorta the inverse of the above question) because you'll hate yourself when you have to rip all that stuff out. In comparison, wrapping out some XML config might not be as painful.
4. What's your shop like? I had trouble pitching a couple of open source options just because of the "gasp! it's not Microsoft!" reactions. If you're a straight MS shop, using Unity will be a much easier cultural win.

On a personal note:

I've used StructureMap for the same reasons mentioned in the blog I linked. I think XML config is a giant pain to maintain and, especially, debug (see WCF). I haven't tried Ninject yet, but based on their marketing, it must be super rad!

Answer 2

I think the choice comes down to finding a framework that meets your requirements and then personal preference.

Does your project already use a library such as rhino-tools that already integrates with a DI framework? If it does, that might be a good starting point if you want to avoid using "lots of different dependency injection frameworks".

Check out these two posts:

• SO: Enterprise Library Unity vs Other IoC Containers
• SO: Which .NET dependency injection framework do you use?

Answer 3

Spring and Unity are Xml heavy.

I would disagree with that statement for Unity; you can write

container.RegisterType<IRobot, MrRoboto>();

and do your setup in code using a fluent-style interface. Personally I like Unity.

Answer 4

It's hard to answer which framework is 'best', but I can tell you which framework is the easiest: The Simple Injector:

The Simple Injector is an easy-to-use Inversion of Control library for .NET and Silverlight. It solely supports code-based configuration and is an ideal starting point for developers unfamiliar with larger IoC / DI libraries

http://simpleinjector.codeplex.com/

Shameless plug btw ;-)