Using Structuremap IoC framework example

What is Structuremap?

It is one of the oldest IoC container frameworks which created by Jeremy Miller around June 2004. It is a stable open source framework that used in many projects. You can download it from Nuget .

What we have ?

We have a printer class that accepts printer type and do printing according to the passed type.

print class

public class Print {
        private readonly ITypeOfPrinter _typeOfPrinter; 
        public Print(ITypeOfPrinter typeOfPrinter) {
            _typeOfPrinter = typeOfPrinter;
        } 
 
        public string print() {
          return _typeOfPrinter.Printing();
        }
}

The passed type can be Black and white or colorfull

Type of printer

public class BlackAndWhitePrinter : ITypeOfPrinter {
        public string Printing() {
            NumberOfPrints++;
            return string.Format("it is Black and white printing {0}",NumberOfPrints); 
        }
 
        public int NumberOfPrints { get; set; }
}

How to use StructureMap

The structuremap using lambda syntax and we can registering the types with For and Use keywords.

structuremap container

var container = new Container();
container.Configure(x=>x.For<ITypeOfPrinter>().Use<ColorfullPrinter>());
var printerInstance = container.GetInstance<Print>();
string colorfullPrintText = printerInstance.print();

In this example we ask the constructor of the Print class to use the colorful printer type when it’s looking for ITypeOfPrinter.

Using Structuremap with dependency

It is also possible to pass the dependency to the container directly rather than using the Configure method.

structuremap with dependency

var container = new Container(x => x.For<ITypeOfPrinter>().Use<ColorfullPrinter>());
var printerInstance = container.GetInstance<Print>();
string colorfullPrintText = printerInstance.print();

Registering all the dependencies in one place

We can use Registry class in the Structure map. Configuration. DSL name space to registering the dependencies in a separate method.

In this case we should implement this class and passing the registration in its constructor.

registering

public class Registering:Registry {
        public Registering() {
            For<ITypeOfPrinter>().Use<BlackAndWhitePrinter>();
        }
}

Then we can initialize our container easily by calling this method.

Using structuremap with dependency

var container = new Container(new Registering());
var printerInstance = container.TryGetInstance<ITypeOfPrinter>();
string blackAndWhitePrintText = printerInstance.Printing();

Unity singleton Lifecycle

Similar to the other IoC framework by default every time we resolve a class it make a new instance of it. In order to treat it as a singleton and using the static properties we can use SingeltonLifecycle() method.

singelton lifecycle

var container = new Container();
container.Configure(x=>x.For<ITypeOfPrinter>().LifecycleIs(new SingletonLifecycle()).Use<BlackAndWhitePrinter>());
var printerInstance = container.GetInstance<Print>();
var printerInstance2 = container.GetInstance<Print>(); 
string blackAndWhitePrintText = printerInstance.print();
string blackAndWhitePrintText2 = printerInstance2.print();

In this case the printer and print2 has a different number of prints values.

Download

Feel free to download the full source code of this example from my GitHub.