CODEWITHSUNDEEP
asp.netasp.net-mvc
dumbledad
dumbledad

Reputation: 17527

ASP.Net 5 configuration dependency injection and static controller constructors

ASP.Net 5 offers an options pattern to easily convert any POCO class into a settings class. Using this I can write my settings in json and then turn them into a typed object that I can inject into my controllers. So, for example, my ConfigureServices method in Startup.cs contains the line 

services.Configure<AppSettings>(Configuration.GetSection("AppSettings"));

and then this gets passed into my controllers' constructors using dependency injection

public ItemsController(IOptions<AppSettings> settings) { /* do stuff */ }

One of my controllers fires up a DNN to do some of its work. To reduce the cost of starting the DNN I do that from the static class constructor. Static constructors are parameterless and so I cannot pass in the required settings object, but I could set a static IOptions<AppSettings> property on the ItemsController from my ConfigureServices method. How do I get at that? Where is the dependency injector and how do I persuade it to hand me an IOptions<AppSettings>?

Upvotes: 2

Views: 1202

Answers (1)

NightOwl888
NightOwl888

Reputation: 56869

I think you are looking at the problem wrong. The problem is that you have a static class and are using DI, not how to inject your dependencies into a static class (which cannot be done without resorting to a service locator or another hack).

Most DI containers have a singleton lifestyle, which allows you to share the same instance of an object across your application. Using this approach, there is no need for a static class. Eliminate the static class by replacing it with an singleton instance, and you have an avenue where you can inject dependencies into your constructor.

Upvotes: 5

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