.NET Core - Understanding Scoped, Transient, and Singleton Lifetime

Scoped, Transient, and Singleton are three lifetime options available in .NET Core for registering and managing services within the dependency injection container. Understanding these options is crucial for building scalable and maintainable applications. Let's explore each of them:

1. Transient Lifetime:

   A transient service is created each time it is requested from the dependency injection container. This means a new instance is created for every resolution. Transient services are suitable for lightweight and stateless components that don't require shared state. For instance, if you have a service that performs simple calculations or generates random numbers, using the transient lifetime is appropriate.

   To register a transient service in .NET Core, you can use the 'AddTransient' method during service registration:

   services.AddTransient<ITransientService, TransientService>();

2. Scoped Lifetime:

   A scoped service is created once per request or scope. In a web application, a scope typically corresponds to an HTTP request. Within a scope, the same instance of the service is shared across all components that request it. When the scope ends, the scoped service is disposed of. Scoped services are useful for components that require shared state within the scope of a single operation. For example, a database context or a unit of work pattern implementation can be registered as scoped.

   To register a scoped service in .NET Core, you can use the 'AddScoped' method during service registration:

   services.AddScoped<IScopedService, ScopedService>();
   

3. Singleton Lifetime:

   A singleton service is created only once during the lifetime of an application. This means the same instance is shared across all requests and components. Singleton services are suitable for stateful components that need to maintain their state across multiple requests or for services that are expensive to create. For instance, a service that connects to an external resource like a database or a file system can be registered as a singleton.

   To register a singleton service in .NET Core, you can use the 'AddSingleton' method during service registration:

   services.AddSingleton<ISingletonService, SingletonService>();
   

Choosing the appropriate lifetime option is essential for managing resources efficiently and avoiding unnecessary overhead. By understanding the differences between Transient, Scoped, and Singleton lifetimes in .NET Core, you can make informed decisions when registering services in your applications. Consider the nature of your service and the requirements of your application to determine the most suitable lifetime option.

I hope this explanation helps you understand the concept of Scoped, Transient, and Singleton lifetimes in .NET Core.
Happy coding!!😊