Question

我正在尝试实施演示应用程序以了解Unity和IoC。但我有点震惊。

我有错误：

尝试创建类型的控制器时发生错误＆＃39; ProductController的＆＃39 ;.确保控制器具有无参数公共建设者。

以下是我正在做的事情的简要概述：

我有五个项目：

数据模型
商业服务
的WebAPI
商业实体
解析器

我正在关注此代码项目教程： https://www.codeproject.com/articles/997216/restful-day-sharp-resolve-dependency-of-dependenci

我已经完成第3天了。但是我无法解决问题。

这是我的WebApi Project Unity RegisterTypes函数。

public static void RegisterTypes(IUnityContainer container)
{
    // NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
    // container.LoadConfiguration();

    // TODO: Register your types here
    //container.RegisterType<IProductServices, ProductServices>();

    //Component initialization via MEF
    ComponentLoader.LoadContainer(container, ".\\bin", "WebApi.dll");
    ComponentLoader.LoadContainer(container, ".\\bin", "BusinessServices.dll");
}

这是ProductController构造函数

public class ProductController : ApiController
{
    private readonly IProductServices _productServices;

    #region Public Constructor

    /// <summary>
    /// Public constructor to initialize product service instance
    /// </summary>
    public ProductController(IProductServices productServices)
    {
        _productServices = productServices;
    }

    #endregion

BusinessServices项目正在DependencyResolver类

using Resolver;
using System.ComponentModel.Composition;

namespace BusinessServices
{
    [Export(typeof(IComponent))]
    public class DependencyResolver : IComponent
    {
        public void SetUp(IRegisterComponent registerComponent)
        {
            registerComponent.RegisterType<IProductServices, ProductServices>();
        }
    }
}

有人能帮助我吗？

谢谢！

Answer 1

您需要注册所需的类型：

        container.RegisterType<ProductController>();
        container.RegisterType<IProductServices, ProductServices>();

鉴于您已使用Unity IDependencyResolver.GetService实施了container，例如：

    public object GetService(Type serviceType)
    {
        if(container.IsRegistered(serviceType))
        {
            return container.Resolve(serviceType);
        }
        return null;
    }

可以这样做一个简单的演示：

public class UnityResolver : IDependencyResolver
{
    public IUnityContainer _container;

    public UnityResolver()
    {
        _container = new UnityContainer();
        RegisterTypes(_container);
    }

    public IDependencyScope BeginScope()
    {
        return this;
    }

    public object GetService(Type serviceType)
    {
        if(_container.IsRegistered(serviceType))
        {
            return _container.Resolve(serviceType);
        }
        return null;
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return Enumerable.Empty<object>();
    }

    public void Dispose()
    {
    }

    public static void RegisterTypes(IUnityContainer container)
    {
        // NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
        // container.LoadConfiguration();

        // TODO: Register your types here
        container.RegisterType<ProductController>();
        container.RegisterType<IProductServices, ProductServices>();

        //Component initialization via MEF
        //ComponentLoader.LoadContainer(container, ".\\bin", "WebApi.dll");
        //ComponentLoader.LoadContainer(container, ".\\bin", "BusinessServices.dll");
    }
}

并在Application_Start中设置解析器：

GlobalConfiguration.DependencyResolver = new UnityResolver();

Unity和IoC无法正常工作

1 个答案: