Tuesday, June 30, 2015

Dependency Injection with Autofac: Registration Ordering

This post will be part of on going series for Dependency Injection with Autofac. If you have not gone through my previous post I would encourage you to go through it. Followings are links for that.

Dependency Injection with Autofac – Getting Started
Dependency Injection with Autofac – Constructor Injection
Dependency Injection with Autofac- Modules Feature

In this this blog we are going to learn about Registration ordering in Autofac.  If you register same interface multiple times then by default the last registration will be preserved. So when you resolve things it will be resolved by last registration. You can also prevent that via “PreserveExistingDefaults” method which is a second behaviour where first registration will be preserved. We will look both in details in this post.

Registration Ordering:

To demonstrate registration ordering, We are going to create a simple Employee class like below.

After creating a Employee class following is a code for my console application.

If you see code carefully, The important thing is two functions “DefaultBehaviour” and “AnotherBehaviour”. First function I’ve register two employee object one by one then. I tried to resolve employee object and with the help of "PrintEmployee" method I have printed Employee object.  Here I’ve used default behaviour so it will print secondEmployee as last registration will be resolved.

While in “AnotherBehaviour” function, I have used “PreserveExistingDefaults” function while registering secondEmployee object. So it will preserve first registration. So when you resolve object it will resolve first registration. So when you print employee object with “PrintEmployee” method it will print firstEmployee object.

When you run this console application. Following will be output as expected.


That’s it. Hope you like it. Stay tuned for more!.
You can find complete source code this Autofac series on Github at - https://github.com/dotnetjalps/AutofacSamples
Sunday, June 28, 2015

Dependency Injection with Autofac : Modules feature

I’m having fun with Autofac as IOC containers and this is third post in series. In this blog post we are going to learn about Autofac modules. If you have not gone through first two blog posts then I would encourage you to go through it. Followings are link for that.

Dependency Injection with Autofac- Getting Started
Dependency Injection with Autofac – Constructor Injection

What is Autofac Modules?

Autofac modules provides greater flexibility  for structuring large application. Register all the component in single class will work for small applications. But for larger applications that will be quite difficult class. In this situation Autofac modules can help.  Autofac modules allow us to break registrations of component in different classes. Then later all you can load all the modules at single places.

So what we are waiting for, Let’s write some code to demonstrate the power of Autofac Modules. For that I’ve created a simple console application called “AutofacModules” and added Autofac nuget package to get reference of application. In this application we are going to create two separate module for “Student” and “Teachers”. So lets start by creating student model class like following.

Following is a student repository interface which contains a "Print" Method to print Student.
 And here is the implementation for Student Repository Inteface.

Now it's time to create Teacher model class like following.

Following is a interface created for Teacher repository which contains "Print" Method to print Teacher.
And here is the implementation of Teacher repository interface.
Now we are done with creating basic classes and interfaces for Student and Teacher It's time to create a modules for them. To created a module for them we need to create a separate class for Teacher and Student Module which got inherited from the Autofac module class. Following is a code of Student module.
And same for teacher module.
 If you see code of both classes carefully then you will realize that it is inherited from the Module classes and It's got a Load method override where we have done registration of repositories. Now our modules are also ready so It's time to write our main console application code. Following is a code for that.
If you see above code carefully the important thing is "BuildContainer" method where I've registered our module with RegisterModule method.Rest I have created teacher and student object and created object with Autofac Container and print respective objects. When you run application following is a output as expected.


That’s it. Hope you like it. Stay tuned for more post about Autofac features.
You can find whole source code of this Autofac series at Github on following location -https://github.com/dotnetjalps/AutofacSamples
Saturday, June 27, 2015

Dependency Injection with Autofac : Constructor Injection

Recently I’m playing with Autofac and I’m having fun with it. This blog post a part of same series. In this blog post we are going to look into how we can do constructor injection with Autofac. If you are not familiar with Autofac you can go through my introductory blog at following location.

Dependency Injection with Autofac: Getting Started

In this blog, We are going to see how we can do constructor injection with Autofac. So for that I’ve created a small console application. After creating a application, first thing you need to do is to add reference of Autofac via Nuget Package. You can do that via following nuget package.

Now it’s time to write some code. I’ve created a sample basic “Employee” model class like following.

After that I’ve created a interface “IEmployeeRepository” which has one method to print employee and expects Employee object parameter.

And following is a implementation class for Employee Repository.

Now it’s time to write Employee Service class code like following.

If you see above class carefully, You can see that it’s expect a constructor parameter of Employee Repository parameter and there we need to constructor injection.  So let’s write some Autofac code for constructor injection like following.

Here in the above code, You can see I have “BuildContainer” static method. Which created a Container Builder object and It’s register type of employee repository and employee service and it’s return a container object. In main method code I’ve resolve employee service class object with container and it’s automatically inject our constructor requirement of employee service class. Then I’ve created a employee class object and print it with print method. Once you run the application. You will get following output as expected.


That’s it. You can see it’s very easy to do constructor injection with Autofac. In future post we are going to look at some other features provided by Autofac. Stay tuned for more.
You can find complete example of above blog post at following location on github- https://github.com/dotnetjalps/AutofacSamples

Dependency injection with Autofac : Getting started

I have been using dependency injection a lot in my projects. As it’s provide great flexibility to wire up things. Recently in free time I have been looking into some of open source architecture like Orchard and Nopcommerce. Both are using Autofac as dependency injector. As this IOC container are used in one of top successful project I got interested in Autofac and I started learning Autofac. I thought it will be a good idea to start a blog series for my learning so other can get benefit of it.

What is Autofac?

As per Autofac.org a site for Autofac
Autofac is an addictive Inversion of Control container for .NET 4.5, Silverlight 5, Windows Store apps, and Windows Phone 8 apps.
It is used in lots of application and one of the most popular IOC container in .NET world.  As per official documentation here is the basic pattern for integrating Autofac in your application.
  • Structure you application with Inversion of Control in mind
  • Add Autofac references( I prefer it using Nuget Package).
  • At application startup create a container builder
  • Register a component
  • Build container and store it for a later use.
  • Create lifetime scope of container during application execution.
  • Use lifetime scope to resolve instances of application.

Autofac Example:

So what we are waiting for, Let’s create a simple example. I’m going to create a sample application like following.


After creating application, I have created a my interface IPrintService as following.
namespace AutoFacBasic
    public interface IPrintService
        void PrintSomething(string text);

Here is the implementation of interface in class like following.
using System;

namespace AutoFacBasic
    public class PrintService : IPrintService
        public void PrintSomething(string text)

Now, We have done with basic stuff so it’s time to wire up component with Autofac. To add references for Autofac I’m going to use following nuget package.


After adding a Autofac reference via nuget package. I have written following code for that sample console application.
using Autofac;
using System;

namespace AutoFacBasic
    class Program
        static void Main(string[] args)
            //registering interface with class that implemented
            var builder = new ContainerBuilder();

            //Resolving inteface with autofac
            var container = builder.Build();
            var printService = container.Resolve<IPrintService>();
            printService.PrintSomething("Hello World");


Here in the above code, If you see carefully. First I have created a object of Container Builder and then I have register type with print service. Then I have build container builder to get container object. After that I have resolved print service with container and get the object of printer service. Then I have printed Hello world with PrintSomeThing method. When you run application. Here is the output as expected.


That’s it. You can see how easily we can wire up things with Autofac. In future posts we will see some advance features of Autofac. Stay tuned for more!!.

You can find complete source code of this application at following location at github- https://github.com/dotnetjalps/AutofacSamples/
Wednesday, June 24, 2015

Completed 725 blog post and still counting

I’m not a fan of counting milestones but today it was huge one so I could not resist myself to write a blog post about it. Today this blog has been completed 725 Blog post.

I still could not believe this blog has come so far!. This will would not have been possible without you guys.

I promise that I try to keep updated this blog in weekly.  Also on this occasion I would also like to thank my family. Specially my wife who is continuously supporting me and sacrifice her time for my blog post.

Thanks you all again! . Also today I have changed my blog theme to a modern look. Hope you like it. Stay tuned for more. Keep reading my blog. 
Saturday, June 13, 2015

Double quotes not working with Visual Studio

Recently, In one of the development machine with Windows 7, I was having strange problem with Visual Studio 2013, When I type double quote first time it was not there and then after once again type I type then it was there. I was wondering what is going on. After digging into little deep, We figure out it was due to language settings and that is creating problem. After fixing languages I was able to fix this issue. I thought it will be good idea to write a blog post about it. So other can be benefits also.

So problem I was having is I have to type double quotes two times. To fix that problem first thing you need to do is Goto  control panel-> region and language options. There you need to go to Keyboard tab. In windows 8.1 Go to search and search for language preferences.

Once you go to language preferences select English US Keyboard. Set that as default.
Now once you are done with your control panel settings. It’s time to make settings changes in Visual Studio. To Change the settings in visual studio go to Tools –> Options –> Environment Settings –> International Settings.

Support this blog-Buy me a coffee

Buy me a coffeeBuy me a coffee
Search This Blog
Subscribe to my blog


My Mvp Profile
Follow us on facebook
Blog Archive
Total Pageviews