We know that .NET has its own built-in IoC container. When you create web applications, the project templates include the defautl IoC container so that you can focus on your application logic.
Although are are using MVC for this demo, you can use these configurations for Web APIs or any other type of projects, as long as you are using same interfaces to bootstrap the application.
Autofac Extension Package
Now, we will have to add the reference to the
Autofac.Extensions.DependencyInjection package from NuGet.
Attach to Host
In this section, let’s attach the
AutofacServiceProviderFactory to the
Program.cs file from the project and let’s modify the main method to add the provider factory as shown in below code snippet.
Startup class mainly contains two methods:
- Configure method, which defines the request processing pipeline for the .NET Core web app
- ConfigureServices method, which is for configuring the services which would be used by the application.
Now, you can add third method
ConfigureContainer method to bootstrap the Autofac container. You can also create environment specific
ConfigureContainer method by inserting environment name in between as explained in this post.
Let’s create 4 interfaces as shown in below code snippet. First interface contains the method that we will use to return the object creation time.
Then we also have three helper interfaces to demonstrate when (time) objects are created and disposed in the container. These three interfaces are just marker interfaces to demonstrate the service lifetimes.
Then let’s implement a class which implements all the three special interfaces as shown below.
Create Root Module
Create a new class
AutofacRootModule. In the root module now, and register the interfaces to the container as shown below.
Here, we need to modify two things, the controller action and the corresponding view. For the sake of simplicity, let’s modify the Index action and its view.
Inject the interfaces in the controller.
Then read the property
CreatedOn and populate it in the
ViewData collection in the
Next, show those values on
Index view. The sample HTML is also shown in below code snippet.
Run and Verify
Now our application should compile successfully and should be ready to run.
If we run the application now, we should be able to see the created times as shown in below snapshot.
If the page is refreshed, the singleton creation time would stay same always. And every time the page is refreshed, the creation time for scoped and transient object would change.
By the way, did you see that the scoped and transient objects are getting created at exactly the same time. Can you guess why ?
Let me know your thoughts in the comments section.