Unity VContainer - High-Performance DI for Unity

Overview

VContainer is a high-performance IoC container for Unity, providing dependency injection patterns for testable and maintainable code.

Core Topics:

• Constructor and method injection
• Service registration patterns (Singleton, Transient, Scoped)
• LifetimeScope hierarchies
• MonoBehaviour injection
• Factory patterns with DI
• Testing with mocks

Foundation Required: unity-csharp-fundamentals (TryGetComponent, FindAnyObjectByType, null-safe coding)

Learning Path: DI fundamentals → VContainer basics → Advanced patterns → Testing

Quick Start

using VContainer;
using VContainer.Unity;

// Define service interface
public interface IPlayerService
{
    void Initialize();
}

// Implement service
public class PlayerService : IPlayerService
{
    public void Initialize() => Debug.Log("Player initialized");
}

// Setup LifetimeScope
public class GameLifetimeScope : LifetimeScope
{
    protected override void Configure(IContainerBuilder builder)
    {
        builder.Register<IPlayerService, PlayerService>(Lifetime.Singleton);
        builder.RegisterComponentInHierarchy<PlayerController>();
    }
}

// Inject into MonoBehaviour
public class PlayerController : MonoBehaviour
{
    [Inject] private readonly IPlayerService mPlayerService;

    void Start() => mPlayerService.Initialize();
}

Key Concepts

Lifetime Scopes

• Singleton: One instance per container
• Transient: New instance every resolve
• Scoped: One instance per scope

Injection Types

• Constructor Injection: Preferred for required dependencies
• Method Injection: For optional dependencies
• Property/Field Injection: Use [Inject] attribute

Reference Documentation

See VContainer Best Practices for detailed patterns.

Best Practices

1. Register interfaces: Loose coupling and testability
2. Constructor injection first: Explicit dependencies
3. Avoid Service Locator: Don't resolve in Update loops
4. Test with mocks: Use ContainerBuilder in tests
5. Clear hierarchies: Root → Scene → Local scopes