Windsor LifeStyle - Shared instance per Graph

Question

I have 2 types of ViewModel\'s

      public class ViewModelA 
      {
          IService service;
          private ViewModelB childViewModel; 

                  


        

Answer 1

You may be able to use Scoped Lifestyles. Here's an example of some unit tests that seem to do what you want:

[Fact]
public void VMsInSameScopeSharesService()
{
    var container = new WindsorContainer();
    container.Register(Component.For().LifestyleTransient());
    container.Register(Component.For().LifestyleTransient());
    container.Register(Component
        .For().ImplementedBy().LifestyleScoped());

    using (container.BeginScope())
    {
        var a = container.Resolve();

        Assert.Equal(a.service, a.childViewModel.service);
    }
}

[Fact]
public void VMsInDifferentScopesDoNotShareServices()
{
    var container = new WindsorContainer();
    container.Register(Component.For().LifestyleTransient());
    container.Register(Component.For().LifestyleTransient());
    container.Register(Component
        .For().ImplementedBy().LifestyleScoped());

    IService service1;
    using (container.BeginScope())
    {
        var a = container.Resolve();

        service1 = a.service;
    }
    IService service2;
    using (container.BeginScope())
    {
        var a = container.Resolve();

        service2 = a.service;
    }

    Assert.NotEqual(service1, service2);
}

However, this is quite an exotic requirement, which makes me wonder why you want it to behave exactly like this, or if you couldn't structure your code in a way that would make this simpler.