Avoid AsyncScopedLifeStyle in ServiceCollection Integration as Default

[sephit]

In SimpleInjectorServiceCollectionExtensions

Hi

I've been trying to use ServiceCollection Integration on a Win Form Project which is defined as Transient in the DefaultLifestyle but i have a problem whenever I use the ServiceCollection Integration, exactly in the AddSimpleInjector method which try change the DefaultScopedLifeStlye (which is null in the first place).

// Set lifestyle before calling setupAction. Code in the delegate might depend on that.
TrySetDefaultScopedLifestyle(container);

private static void TrySetDefaultScopedLifestyle(Container container)
{
    if (container.Options.DefaultScopedLifestyle is null)
    {
        container.Options.DefaultScopedLifestyle = new AsyncScopedLifestyle();
    }
}

It throws an exception related that the DefaultScopedLifestyle shouldn't be changed after initialization..

Is this the expected behavior?

Why should it changed to a AsyncScopedLifeStyle if i am working with a Transient lifestyle?

[dotnetjunkie]

Is this the expected behavior?

Yes, it is.

Why should it changed to a AsyncScopedLifeStyle if i am working with a Transient lifestyle?

In order to answer this question, I need more information for you. Can you show me:

• What you are using the Service Collection for in your Win Forms application
• How you are doing this integration (show you bootstrapping code)
• What exception you are getting (stack trace and exception message would be appreciated)
• What and how you are changing the Options.DefaultLifestyle' and Options.DefaultScopedLifestyle' options with and why.

[sephit]

Thanks for your answer,

What you are using the Service Collection for in your Win Forms application

To add loggin and another libraries like EasyCaching which only use the ServiceCollection.

How you are doing this integration (show you bootstrapping code)

For example, the following code in a Win Forms application.

var container = new Container();
container.Register(
    () => new ServiceFactory(container.GetInstance),
    Lifestyle.Singleton);

var services = new ServiceCollection()
    .AddLogging()
    .AddEasyCaching(options =>
    {
        options.UseInMemory(config =>
        {
            config.DBConfig = new InMemoryCachingOptions
            {
                ExpirationScanFrequency = 0,
                SizeLimit = 100
            };
        },
        name: "InMemory");

    })
    .AddMediatR(typeof(Program))
    .AddSimpleInjector(container)
    .BuildServiceProvider(validateScopes: true)
    .UseSimpleInjector(container);      

What exception you are getting (stack trace and exception message would be appreciated)

InvalidOperationException: The DefaultScopedLifestyle property cannot be changed after the first registration has been made to the container.

What and how you are changing the Options.DefaultLifestyle' and Options.DefaultScopedLifestyle' options with and why.

I'm not changing the DefaultLifeStyle neither the DefaultScopedLifestyle. Both are using the default value.

Options.DefaultLifeStyle = Transient
Options.DefaultScopedLifestyle = null

[dotnetjunkie]

Ah, I see. The exception tells you as it is:

var container = new Container();
container.Register<ServiceFactory>(...);  <!-- Your first registration

var services = new ServiceCollection()
    .AddLogging()
    ...
    .AddSimpleInjector(container) <!-- AddSimpleInjector expected no registrations.
    ...

The solution is to move the ServiceFactory registration down:

var container = new Container();

var services = new ServiceCollection()
    .AddLogging()
    ...
    .AddSimpleInjector(container)
    ...

container.Register<ServiceFactory>(...);  <!-- Registered after the AddSimpleInjector call.

As you noticed, AddSimpleInjector might set the Options.DefaultScopedLifestyle, but this value can only be set as long as there are no registrations made in the Container. This means you need to set it very early in the setup phase. Reason for this is that the already-made registrations might be done using the default scoped lifestyle. Changing this lifestyle half-way the registration process might result in two different types of scoped lifestyles being used, which could result in very weird behavior. That's why Simple Injector blocks this.

Alternatively, you can set the DefaultScopedLifestyle manually:

var container = new Container();
container.Options.DefaultScopedLifestyle =new AsyncScopedLifestyle();
container.Register<ServiceFactory>(...);  <!-- Your first registration

var services = new ServiceCollection()
    .AddLogging()
    ...
    .AddSimpleInjector(container)
    ...

This works because AddSimpleInjector will not try to set the DefaultScopedLifstyle if it's already set.