将对象转换为通用接口

我有以下界面:

internal interface IRelativeTo where T : IObject
{
    T getRelativeTo();
    void setRelativeTo(T relativeTo);
}

和一堆(应该)实现它的类,例如:

public class AdminRateShift : IObject, IRelativeTo
{
    AdminRateShift getRelativeTo();
    void setRelativeTo(AdminRateShift shift);
}

我意识到这三个不一样:

IRelativeTo<>
IRelativeTo
IRelativeTo

但是,我需要一种方法来处理所有不同的类,如AdminRateShift(和FXRateShift,DetRateShift),它们都应该实现IRelativeTo.假设我有一个函数将AdminRateShift作为Object返回:

IRelativeTo = getObjectThatImplementsRelativeTo(); // returns Object

通过对接口进行编程,我可以做我需要的,但我实际上无法将对象转换为IRelativeTo,所以我可以使用它.

这是一个微不足道的例子,但我希望它能澄清我想要做的事情.

如果我理解这个问题,那么最常见的方法是声明一个非通用的基接口,即

internal interface IRelativeTo
{
    object getRelativeTo(); // or maybe something else non-generic
    void setRelativeTo(object relativeTo);
}
internal interface IRelativeTo : IRelativeTo
    where T : IObject
{
    new T getRelativeTo();
    new void setRelativeTo(T relativeTo);
}

另一种选择是你在泛型中很大程度上编码...即你有类似的方法

void DoSomething() where T : IObject
{
    IRelativeTo foo = // etc
}

如果IRelativeTo是一个参数DoSomething(),那么通常你不需要自己指定泛型类型参数 - 编译器会推断它 - 即

DoSomething(foo);

而不是

DoSomething(foo);

这两种方法都有好处.

void MyFunction(IRelativeTo sth) where T : IObject
{}

interface IRelativeTo
 {
   IObject getRelativeTo();
   void setRelativeTo(IObject relativeTo)
 }

abstract class RelativeTo  : IRelativeTo where T : IObject
 {  
   public virtual T getRelativeTo() {return default(T);}

   public virtual void setRelativeTo(T relativeTo) {}

   IObject IRelativeTo.getRelativeTo() {return this.getRelativeTo(); }

   void IRelativeTo.setRelativeTo(IObject relativeTo) 
    { this.setRelativeTo((T) relativeTo);
    }
 }

class AdminRateShift :  RelativeTo, IObject {}

  IRelativeTo irt = new AdminRateShift();
  IObject o = irt.getRelativeTo();
  irt.setRelativeTo(o);