asp.net core服務的生命週期

時間 2020-06-03

標籤 asp.net asp core 服務生命週期欄目 ASP 简体版

原文原文鏈接

Transient：每一次GetService都會建立一個新的實例html

Scoped：在同一個Scope內只初始化一個實例，能夠理解爲（每個request級別只建立一個實例，同一個http request會在一個 scope內）測試

Singleton：整個應用程序生命週期內只建立一個實例 ui

上面描述的比較抽象，不容易理解，用實例來說解會比較直觀。spa

下面經過具體的例子進行演示。code

定義三個空的接口：IArticleService、IProductService、IUserServicehtm

而後定義三個實現：ArticleService、ProductService、UserServiceblog

1.將接口和實現注入到DI容器接口

在StartUp類的ConfigureServices方法添加下圖代碼生命週期

public void ConfigureServices(IServiceCollection services) { services.AddMvc(); services.Configure<Test>(Configuration.GetSection("Test")); //演示生命週期
            services.AddTransient<IUserService, UserService>(); services.AddScoped<IArticleService, ArticleService>(); services.AddSingleton<IProductService, ProductService>(); }

2.添加私有字段，在測試Controller：LifeTimeController中添加下圖代碼開發

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.添加構造方法

public LifeTimeController( IUserService userService1, IUserService userService2, IArticleService articleService1, IArticleService articleService2, IProductService productService1, IProductService productService2 ) { _userService1 = userService1; _userService2 = userService2; _articleService1 = articleService1; _articleService2 = articleService2; _productService1 = productService1; _productService2 = productService2; }

4.添加測試代碼

public IActionResult Index() { var sb = new StringBuilder(); 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"; return Content(sb.ToString()); }