注射依赖转换为Web API控制器 [英] Injecting Dependency into Web API Controller

问题描述

我要注入团结容器放入WebController。

I want to inject unity container into WebController.

我有UnityDependencyResolver：

I have UnityDependencyResolver:

public class UnityDependencyResolver : IDependencyResolver
{
    readonly IUnityContainer _container;

    public UnityDependencyResolver(IUnityContainer container)
    {
    this._container = container;
    }

    public object GetService(Type serviceType)
    {
        try
        {
            return _container.Resolve(serviceType);
        }
        catch
        {
            return null;
        }
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        try
        {
            return _container.ResolveAll(serviceType);
        }
        catch
        {
            return new List<object>();
        }
    }

    public void Dispose()
    {
        _container.Dispose();
    }
}

然后，在我的Global.asax我添加了以下行：

Then, in my Global.asax I add the following line:

var container = new UnityContainer();
container.RegisterType<IService, Service>
(new PerThreadLifetimeManager()).RegisterType<IDALContext, DALContext>();
DependencyResolver.SetResolver(new UnityDependencyResolver(container));

然后，如果我用下面的在Web控制器：

Then, If I use the following in a Web Controller:

private IService _service;

public HomeController(IService srv)
{
    _service = srv;
}

它工作正常。

但我想它注入的WebAPI控制器，​​所以如果我做同样的方式：

But I want to inject it into WebAPI Controller, so if I do it the same way:

private IService _service;

public ValuesController(IService srv)
{
    _service = srv;
}

这是不行的，它说，构造函数没有定义。
好吧，我再创建一个构造函数：

It does not work, it says that constructor is not defined. Ok, I create one more constructor:

public ValuesController(){}

而在这种情况下，仅使用此构造，从来没有一个，我应该团结注入容器。

And in this case it uses only this constructor and never the one where I should inject unity container.

请指教。

推荐答案

在您的WebApiConfig补充一点：

Add this in your WebApiConfig:

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Routes and other stuff here...

        var container = IocContainer.Instance; // Or any other way to fetch your container.
        config.DependencyResolver = new UnityDependencyResolver(container);
    }
}

如果你想在同一容器你可以把它在一个静态变量，像这样：

And if you want the same container you can keep it in a static variable, like so:

public static class IocContainer
{
    private static readonly Lazy<IUnityContainer> Container = new Lazy<IUnityContainer>(() =>
    {
        var container = new UnityContainer();
        return container;
    });

    public static IUnityContainer Instance
    {
        get { return Container.Value; }
    }
}

更多信息可以在这里找到：

More info can be found here:

http://www.asp.net/web-api/概述/高级/依赖注入

在一个旁注，我也可以推荐的NuGet包 Unity.Mvc 。它增加了一个 UnityWebActivator 和支持 PerRequestLifetimeManager 。

On a sidenote, I can also recommend the nuget-package Unity.Mvc. It adds a UnityWebActivator and support for PerRequestLifetimeManager.

https://www.nuget.org/packages/Unity.Mvc/

这篇关于注射依赖转换为Web API控制器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！