C# 具有泛型约束的泛型类型

我有以下几种：

public interface IContainer<in TKey, out TValue>
{
    TValue Resolve(TKey key);
}

public interface IBuilder<out TContainer, in TKey, out TValue> where 
TContainer : IContainer<TKey, TValue>
{
    TContainer Build();
}

public interface IRegister<in TBuilder, TKey, TValue> where TBuilder : 
IBuilder<IContainer<TKey, TValue>, TKey, TValue>
{
    void Register(TBuilder builder);
}

public interface IServiceMessageHandlerTypeContainer<TService, in 
TServiceMessageHandler> 
    : IContainer<TServiceMessageHandler, ECommand>
    where TServiceMessageHandler : class, IMessageHandler<TService>
{

}

public interface IServiceMessageHandlerTypeContainerBuilder<TService, in 
TServiceMessageHandler, out             TServiceMessageHandlerTypeContainer> 
    : IBuilder<TServiceMessageHandlerTypeContainer, TServiceMessageHandler, 
ECommand>
    where TServiceMessageHandler : class, IMessageHandler<TService>
    where TServiceMessageHandlerTypeContainer : 
IServiceMessageHandlerTypeContainer<TService, TServiceMessageHandler>
{
    void Register<TServiceMessageHandlerType>(ECommand command) 
        where TServiceMessageHandlerType : TServiceMessageHandler;
}

public interface IServiceMessageHandlerTypeRegister<
    TService, 
    TServiceMessageHandler, 
    TServiceMessageHandlerTypeContainer, 
    in TServiceMessageHandlerTypeContainerBuilder> 
    : IRegister<TServiceMessageHandlerTypeContainerBuilder, 
TServiceMessageHandler, ECommand>
    where TServiceMessageHandler : class, IMessageHandler<TService>
    where TServiceMessageHandlerTypeContainer 
    : IServiceMessageHandlerTypeContainer<TService, TServiceMessageHandler> 
    where TServiceMessageHandlerTypeContainerBuilder 
    : IServiceMessageHandlerTypeContainerBuilder<TService, 
TServiceMessageHandler, TServiceMessageHandlerTypeContainer>
{

}

公共接口IContainer
{
t值解析（TKey）；
}
公共接口IBuilder在哪里
t容器：i容器
{
t容器构建（）；
}
公共接口IRegister，其中TBuilder：
伊布尔德
{
无效登记簿（TBuilder-builder）；
}
公共接口IServiceMessageHandlerTypeContainer
：i容器
其中TServiceMessageHandler:class，IMessageHandler
{
}
公共接口IServiceMessageHandlerTypeContainerBuilder
：iBilder
其中TServiceMessageHandler:class，IMessageHandler
其中TServiceMessageHandlerTypeContainer：
IServiceMessageHandlerTypeContainer
{
无效寄存器（ECommand命令）
其中TServiceMessageHandlerType:TServiceMessageHandler；
}
公共接口IServiceMessageHandlerTypeRegister<
TService，
TServiceMessageHandler，
TServiceMessageHandlerTypeContainer，
在TServiceMessageHandlerTypeContainerBuilder中>
：i注册
其中TServiceMessageHandler:class，IMessageHandler
其中TServiceMessageHandlerTypeContainer
：IServiceMessageHandlerTypeContainer
其中TServiceMessageHandlerTypeContainerBuilder
：IServiceMessageHandlerTypeContainerBuilder
{
}

我真的无法得到，为什么TServiceMessageHandlerTypeContainerBuilder的约束在这里不好

原因IServiceMessageHandlerTypeContainerBuilder

这是伊布尔德吗

和IServiceMessageHandlerTypeContainer 这是我的容器吗

你知道这里会出什么问题吗

如果我添加contain： 其中TServiceMessageHandlerTypeContainerBuilder ：IServiceMessageHandlerTypeContainerBuilder， IBuilder、TServiceMessageHandler、ECommand>

它起作用了

但这并不是我需要的

编辑： 编译时错误为：

错误CS0314类型“TServiceMessageHandlerTypeContainerBuilder”不能用作泛型类型或方法“IRegister”中的类型参数“TBuilder”。没有从“TServiceMessageHandlerTypeContainerBuilder”到“Patterns.DependencyInjection.Builder.IBuilder、TServiceMessageHandler、DataTransmissionServices.Enums.ECommand>”的装箱转换或类型参数转换

---

某些东西与协方差和逆方差有关吗？

不，它与协方差或逆方差无关。它与通用参数的约束有关

TServiceMessageHandlerTypeContainerBuilder的构造将转到

i文件夹，其中t容器：i容器

但是当您从继承IServiceMessageHandlerTypeRegister时

IRegister<TServiceMessageHandlerTypeContainerBuilder,TServiceMessageHandler, ECommand>

i注册表

约束转到IBuilder、TKey、TValue>。

---

因为IBuilder、TKey、TValue>无法转换为IBuilder，所以您会遇到编译错误。

您所说的“不好”是什么意思？您的意思是这会导致编译时错误吗？如果是，请在问题中包含错误。另外，如果你能减少问题中涉及的类型的数量，那肯定会有助于让问题更清楚。我想我不能减少类型的数量，因为这里的所有类型都可能是错误的原因