Question

I am using the Ninject WCF extension project to do dependency injection on my web service. If I add an attribute to my web service (such as a an IServiceBehavior), how can I inject dependencies into that attribute when it is created at runtime?

Answer 1

Attributes are created by the .NET Runtime. Therefore there is no real dependency injection for them. You should try to avoid having attributes that require dependencies whenever possible. You have the following options:

1. Service behaviors can be added without attributes. But this requires that you extend the current WCF Extension with some way to define that you want to add a service behavior for some instances in a similar way as it is currently possible for MVC Filters. This is done here: https://github.com/ninject/ninject.extensions.wcf/blob/master/src/Ninject.Extensions.Wcf/ServiceHost/NinjectServiceHost.cs
2. You can implement an IInstance provider which searches your attributes and injects them. See https://github.com/ninject/ninject.extensions.wcf/blob/master/src/Ninject.Extensions.Wcf/NinjectInstanceProvider.cs

I’d try to go with the first option.