AddSingleton()与AddSingleton()

本文介绍了AddSingleton()与AddSingleton()的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在我的项目中实现依赖注入.我遇到了两种添加单例服务的方法-

I'm implementing dependency injection in my project. I've come across two ways to add a singleton service -

services.AddSingleton(new MyCustomService())

和

services.AddSingleton<MyCustomService>()

这两种方法似乎都有效.这两种方法有什么区别，我应该使用哪种方法?

Both methods seem to work. What's the difference between these two methods, and which one should I be using?

推荐答案

使用通用 .AddSingleton< TService>()方法(和 .AddSingleton< TService，TImplementation>()时，该类型由容器创建，控制和处理.当构造函数包含其他依赖项时，这些依赖项会自动注入(一种称为自动装配"的技术).

When using the generic .AddSingleton<TService>() method (and .AddSingleton<TService, TImplementation>(), the type is created, controlled, and disposed of by the container. When the constructor contains other dependencies, those dependencies are automatically injected (a technique called "Auto-Wiring").

使用 .AddSingleton< TService>(TService)提供的实例已经存在.在这种情况下，当容器实现 IDisposable 或 IAsyncDisposable 时，该容器将不处置该实例.您有责任自己处置该实例.

Instances supplied using .AddSingleton<TService>(TService) already exist. In that case, the container will not dispose of that instance when it implements IDisposable or IAsyncDisposable. You are responsible for disposing of that instance yourself.

由于 .AddSingleton< TService>(TService)提供了一个已经存在的实例，因此该容器无法注入任何依赖关系，因为为此，它还必须 create实例.

Since .AddSingleton<TService>(TService) is supplied with an already existing instance, the container can't inject any dependencies, because in order to do that, it must also create the instance.