I have been attempting to integrate the Unity Application Block into my website to allow me to share the same base object code between a WPF and an ASP.NET application. I will let you know how I am getting along later as I am still knee deep in refactoring, but I have found something a little useful.
I have created a custom “My” object in Visual Studio. This means that I can do “My.Unity.Container” to retrieve my UnityContainer object form anywhere is my code. I know it my be trivial to achieve in other ways, but I am a VB degenerate having fun, so leave me alone…
The first thing we need is a way of consistently creating a singleton instance of our UnityContainer across all of our code in the AppDomain.
Imports Microsoft.Practices.Unity Public Class UnityContainer Inherits Microsoft.Practices.Unity.UnityContainer Private Shared sm_UnityContainer As Microsoft.Practices.Unity.UnityContainer Private Shared sm_syncRoot As New Object Private Sub New() MyBase.New() End Sub Public Shared ReadOnly Property Current() As Microsoft.Practices.Unity.UnityContainer Get If (sm_UnityContainer Is Nothing) Then SyncLock sm_syncRoot If (sm_UnityContainer Is Nothing) Then sm_UnityContainer = New UnityContainer 'Dim section As UnityConfigurationSection = ConfigurationManager.GetSection("unity") 'section.Containers.Default.Configure(sm_UnityContainer) End If End SyncLock End If Return sm_UnityContainer End Get End Property End Class
I have commented the lines out, but you could also initialise the Unity Container from a config file, but remember that it will be the top level config of your application root an not the config from the Assembly that you code happens to be in.
We could just leave it at that, and If you use C# this is about your lot, but in VB you have the “My” namespace that gives you access to some useful things all in one place.
In order to achieve this you need to create a Module in the “My” namespace that has a single property that access the previous class.
Imports Common Namespace My <HideModuleName()> _ Module MyUnityExtensions Friend ReadOnly Property Unity() As UnityContainer Get Return UnityContainer.Current End Get End Property End Module End Namespace
This the allows you to access the UnityContainer object in the same way that you would access My.User.
Inside the Unity object you will have all of the shared properties and methods that we created earlier.
So, I have a Console application that registers a sword type and the resolves out a Ninja Object using Unity.
Imports NinjaCommon Module Module1 Sub Main() ' Register Weapon My.Unity.RegisterType(Of IWeapon, Sword)() 'Create Ninja Dim ninja = My.Unity.Resolve(Of Ninja)() ' Ninja uses weapon ninja.Weapon.use() ' Create Battle Dim battle As New NinjaClasses.Battle ' Start the fight battle.StartFight() Console.ReadKey() End Sub End Module
But it then instantiates a Battle class from the NinjaClasses assembly which uses it own My.Unity class to access the same UnityContainer object.
Public Class Battle Public Sub New() End Sub Public Sub StartFight() Console.WriteLine("Fight Starting ") ' Create 10 ninjas and get them to use their weapon. For count = 1 To 10 Dim ninja = My.Unity.Resolve(Of NinjaCommon.Ninja)() ninja.Weapon.use() Next Console.WriteLine("Fight ended") End Sub End Class
Although this example in no way demonstrates the power of the Unity Application Block, and is a bit silly, I think it demonstartes the use of the “My” namespace.