Lifetime options in ASP.NET Core

.NET Core’s Dependency Injection (DI) framework provides three-lifetime options for resolving dependencies: Transient, Scoped, and Singleton.

• Transient: A new instance of the service is created each time it is requested.

public void ConfigureServices(IServiceCollection services)
{
    services.AddTransient<IMyDependency, MyDependency>();
}

• Scoped: A single instance of the service is created per client request (e.g., per HTTP request).

public void ConfigureServices(IServiceCollection services)
{
    services.AddScoped<IMyDependency, MyDependency>();
}

• Singleton: A single instance of the service is created the first time it is requested and re-used for all subsequent requests.

public void ConfigureServices(IServiceCollection services)
{
    services.AddSingleton<IMyDependency, MyDependency>();
}

You choose the lifetime that best fits your service’s needs, depending on whether you want a new instance every time or to re-use an existing instance.