How does MvvmCross handle lazy singleton registration

Lazy Singleton Registration

To register a type as a lazy singleton, you can use the following method:

csharp
Mvx.IoCProvider.RegisterSingleton(() => new Foo());

In this example, `Foo` implements `IFoo`, but no instance of `Foo` is created until you call:

csharp
var foo = Mvx.IoCProvider.Resolve();

Once the first instance is created, all subsequent calls to `Resolve()` will return the same instance.

Alternative Syntax for Lazy Singleton Registration

If your class requires constructor dependency injection, you can use an alternative syntax:

csharp
Mvx.IoCProvider.LazyConstructAndRegisterSingleton();

This method also registers `Foo` as a lazy singleton but is more suitable when `Foo` has dependencies that need to be injected during construction.

Benefits of Lazy Registration

Lazy registration is beneficial because it delays the creation of objects until they are actually needed. This can improve application startup times by avoiding unnecessary object creation at the beginning. It also helps manage resources more efficiently, as objects are only instantiated when required.

Example Use Case

Consider a scenario where you have a service class `MyService` that implements `IMyService`. You can register it as a lazy singleton like this:

csharp
public class MyService : IMyService
{
    public MyService(IDependency dependency)
    {
        // Dependency injection
    }

    // Implementation
}

// Registration
Mvx.IoCProvider.LazyConstructAndRegisterSingleton();

Then, when you need to use `IMyService`, you resolve it:

csharp
var myService = Mvx.IoCProvider.Resolve();

The first call to `Resolve` will create the instance of `MyService`, and subsequent calls will return the same instance.

Bulk Registration by Convention

MvvmCross also supports bulk registration of types based on conventions, such as registering all classes ending with "Service" as lazy singletons:

csharp
CreatableTypes()
    .EndingWith("Service")
    .AsInterfaces()
    .RegisterAsLazySingleton();

This approach simplifies the registration process by automatically finding and registering types based on naming conventions.