ASP.NET Web API依赖注入 [英] ASP.NET Web API Dependency Injection

问题描述

我想知道在不使用第三方库（例如Unity或StructureMap）且没有实体框架的情况下，是否可以在ASP.NET Web API中进行依赖项注入（自定义构造函数）。

I would like to know if it is possible to do dependency injection (custom constructor) in a ASP.NET Web API without the use of third party libraries such as Unity or StructureMap and without Entity Framework.

我想实现的是拥有一个带有构造函数的控制器，例如：

What I would like to achieve is have a controller with a constructor such as:

public Controller(IDatabaseConnector connector) { ... }

我知道MVC可以通过以下方式创建自定义ControllerFactory从DefaultControllerFactory继承，然后重写GetControllerInstance函数。因此，我确定还有Web API的替代方法。

I know for MVC you can make a custom ControllerFactory by inheriting from DefaultControllerFactory and then overriding the GetControllerInstance function. So I am sure there is an alternative for Web API.

推荐答案

首先，您应该定义自己的 IHttpControllerActivator ：

At first you should define your own IHttpControllerActivator:

public class CustomControllerActivator : IHttpControllerActivator
{
    public IHttpController Create(
        HttpRequestMessage request,
        HttpControllerDescriptor controllerDescriptor,
        Type controllerType)
    {
        // Your logic to return an IHttpController
        // You can use a DI Container or you custom logic
    }
}

然后应替换默认值 Global.asax 中的激活器：

Then you should replace the default activator in the Global.asax:

protected void Application_Start()
{
    // ...

    GlobalConfiguration.Configuration.Services.Replace(
        typeof(IHttpControllerActivator),
        new CustomControllerActivator());
}

现在，您可以使用功能丰富的 Controller 构造函数：

Now you can use your rich Controller constructor:

public class UserController
{
    public UserController(
        IMapper mapper,
        ILogger logger,
        IUsersRepository usersRepository)
    {
        // ...
    }

    // ...
}

这篇关于ASP.NET Web API依赖注入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！