The life cycle of the ASP. NET Core Service

Transient: Each time a getservice creates a new instance

Scoped: Only one instance is initialized within the same scope, which can be understood as (only one instance is created per request level, and the same HTTP request is within a scope)

Singleton: Only one instance is created throughout the application life cycle

The above description of the comparative abstract, not easy to understand, with examples to explain the more intuitive.

The following is a demonstration with specific examples.

Define three empty interfaces: Iarticleservice, Iproductservice, Iuserservice

Then define three implementations: Articleservice, Productservice, UserService

1. Injecting the interface and implementation into the DI container

Adding code to the Configureservices method of the startup class

         Public void configureservices (iservicecollection services)        {            services. Addmvc ();            Services. Configure<Test> (configuration.getsection ("Test"));             // Demo life cycle            Services. Addtransient<iuserservice, userservice>();            Services. addscoped<iarticleservice, articleservice>();            Services. Addsingleton<iproductservice, productservice>();        }

2. Add a private field to add code to the test Controller:lifetimecontroller

 private  readonly   Iuserservice _userservice1;  private  readonly   Iuserservice _userservice2;  private  readonly   Iarticleservice _articleservice1;  private  readonly   Iarticleservice _articleservice2;  private  readonly   Iproductservice _productservice1;  private  readonly  Iproductservice _productservice2; 

3. Adding a construction method

         Public Lifetimecontroller (            iuserservice UserService1, Iuserservice userService2,            iarticleservice ArticleService1, Iarticleservice articleService2,            iproductservice ProductService1, Iproductservice ProductService2        )        {            = UserService1;             = UserService2;             = ArticleService1;             = ArticleService2;             = ProductService1;             = productService2;        }

4. Add test code

         PublicIactionresult Index () {varSB =NewStringBuilder (); Sb. Append ("transient1:"+ _userservice1.gethashcode () +"<br/>"); Sb. Append ("Transient2:"+ _userservice2.gethashcode () +"<br/>"); Sb. Append ("scope1:"+ _articleservice1.gethashcode () +"<br/>"); Sb. Append ("scope2:"+ _articleservice2.gethashcode () +"<br/>"); Sb. Append ("Singleton1:"+ _productservice1.gethashcode () +"<br/>"); Sb. Append ("Singleton2:"+ _productservice2.gethashcode () +"<br/>"); Response.ContentType="text/html"; returnContent (sb.)        ToString ()); }

5. Implementation results

First time refresh:

transient1:66454027
transient2:35021870
scope1:38350037
scope2:38350037
singleton1:4417230
singleton2:4417230

Second refresh:

transient1:103653
transient2:5079042
scope1:47546512
scope2:47546512
singleton1:4417230
singleton2:4417230

Visible

The life cycle of the transient type is different for each use, and differs from one class to another using different methods.

The life cycle of the scope type is the same within the same request

Singleton type of life cycle, each request is the same

So understanding the role of life cycle, we can in the development of the different services to choose different life cycle.

The life cycle of the ASP. NET Core Service