ASP.NET Core中的IServiceProvider [英] IServiceProvider in ASP.NET Core

问题描述

我开始学习ASP.NET 5(vNext)中的更改 并且找不到如何获取IServiceProvider，例如在模型"的方法中

I starting to learn changes in ASP.NET 5(vNext) and cannot find how to get IServiceProvider, for example in "Model"'s method

public class Entity 
{
     public void DoSomething()
     { 
           var dbContext = ServiceContainer.GetService<DataContext>(); //Where is ServiceContainer or something like that ?
     }
}

我知道，我们在启动时配置服务，但是所有服务集合还是IServiceProvider保留在哪里?

I know, we configuring services at startup, but where all service collection staying or IServiceProvider?

推荐答案

您必须引入Microsoft.Extensions.DependencyInjection命名空间才能访问通用

You have to bring in Microsoft.Extensions.DependencyInjection namespace to gain access to the generic

GetService<T>();

应在

IServiceProvider 

还请注意，您可以将服务直接注入ASP.NET 5中的控制器中.请参见下面的示例.

Also note that you can directly inject services into controllers in ASP.NET 5. See below example.

public interface ISomeService
{
    string ServiceValue { get; set; }
}

public class ServiceImplementation : ISomeService
{
    public ServiceImplementation()
    {
        ServiceValue = "Injected from Startup";
    }

    public string ServiceValue { get; set; }
}

Startup.cs

Startup.cs

public void ConfigureService(IServiceCollection services)
{
    ...
    services.AddSingleton<ISomeService, ServiceImplementation>();
}

HomeController

HomeController

using Microsoft.Extensions.DependencyInjection;
...
public IServiceProvider Provider { get; set; }
public ISomeService InjectedService { get; set; }

public HomeController(IServiceProvider provider, ISomeService injectedService)
{
    Provider = provider;
    InjectedService = Provider.GetService<ISomeService>();
}

这两种方法均可用于访问服务. Startup.cs的其他服务扩展

Either approach can be used to get access to the service. Additional service extensions for Startup.cs

AddInstance<IService>(new Service())

始终提供单个实例.您负责初始对象的创建.

A single instance is given all the time. You are responsible for initial object creation.

AddSingleton<IService, Service>()

创建了一个实例，它的行为就像一个单例.

A single instance is created and it acts like a singleton.

AddTransient<IService, Service>()

每次插入新实例都会创建一个

A new instance is created every time it is injected.

AddScoped<IService, Service>()

在当前HTTP请求范围内创建一个实例.在当前作用域上下文中，它等效于Singleton.

A single instance is created inside of the current HTTP Request scope. It is equivalent to Singleton in the current scope context.

更新于2018年10月18日

请参阅: aspnet GitHub-ServiceCollectionServiceExtensions.cs

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