如何使用 Unity Container 解析的泛型接口作为构造函数参数来解析泛型类答案

【问题标题】：How to Resolve Generic Class With Unity Container Resolved Generic Interface as Constructor Parameter如何使用 Unity Container 解析的泛型接口作为构造函数参数来解析泛型类
【发布时间】：2012-02-06 07:27:01
【问题描述】：

我不知道如何在我的 Unity (2.0) 容器中注册一个具有注入通用接口的通用抽象类。这是接口和类：

public interface IReportFactory<in TEntity, out TReport>
{ ... }

public class ExperienceReportBaseFactory :
    IReportFactory<Experience, ExperienceReportBase>
{ ... }

public abstract class ReportProvider<TEntity, TReport>
{
    protected ReportProvider(
        IReportFactory<TEntity, TReport> reportFactory)
    { ... }
    ...
}

public class ExperienceDetailsReportProvider
    : ReportProvider<Experience, ExperienceReportBase>
{
    public ExperienceDetailsReportProvider(
        IReportFactory<Experience, ExperienceReportBase>
        reportFactory)
        : base(reportFactory) { ... }
    ...
}

这是注册码：

Container.RegisterInstance(typeof(IReportFactory<Experience, ExperienceReportBase>), new ExperienceReportBaseFactory())
         .RegisterType(typeof(ReportProvider<Experience, ExperienceReportBase>),
             typeof (ExperienceDetailsReportProvider),
             new InjectionConstructor(Container.Resolve(typeof (IReportFactory<Experience, ExperienceReportBase>))));

这是我试图解决ReportProvider<,> 的提供程序工厂：

public class ReportProviderFactory<TEntity> : IReportProviderFactory<TEntity>
{
    private readonly IServiceLocator _serviceLocator;

    public ReportProviderFactory(IServiceLocator serviceLocator)
    {
        _serviceLocator = serviceLocator;
    }

    public ReportProvider<TEntity, TReport> Create<TReport>()
        where TReport : ActiveReport
    {
        var reportProvider =
            _serviceLocator.GetService(typeof (ReportProvider<TEntity, TReport>)) as
                ReportProvider<TEntity, TReport>;
        return reportProvider;
    }
}

我在_serviceLocator.GetService(...) 行收到“无法构造类型 ReportProvider`2。您必须配置容器以提供此值”。

【问题讨论】：

标签： generics dependency-injection unity-container ioc-container service-locator

【解决方案1】：

我是个白痴...调用ReportProviderFactory<Experience>.Create<>() 的客户端正在为TReport 指定不同的类型：

var reportProvider = _reportProviderFactory<Experience>.Create<ExperienceDetailsReport>();

这意味着我在 ExperienceReportBaseFactory 和 ExperienceDetailsReportProvider 上的 TReport 类型错误，因为客户端正在使用 .应该是：

public class ExperienceReportBaseFactory : IReportFactory<Experience, ExperienceDetailsReport> { ... }

public class ExperienceDetailsReportProvider : ReportProvider<Experience, ExperienceDetailsReport>
{
    public ExperienceDetailsReportProvider(IReportFactory<Experience, ExperienceDetailsReport> reportFactory) : base(reportFactory) { ... }
    ...
}

【讨论】：