确定类是否是具有多个通用参数的类型的子类

Question

Given the following class hierarchy

public abstract class MyGenericClass<T1, T2> 
{
    public T1 Foo { get; set; }
    public T2 Bar { get; set; }
}

public class BobGeneric : MyGenericClass<int, string>{}
public class JimGeneric : MyGenericClass<System.Net.Cookie, System.OverflowException>{}

I would have thought that I could do the following

//All types in the assembly containing BobGeneric and JimGeneric
var allTypes = _asm.GetTypes();  

//This works for interfaces, but not here 
var specialTypes = allTypes.Where(x => typeof(MyGenericClass<,>).IsAssignableFrom(x))

//This also fails
typeof(BobGeneric).IsSubclassOf(typeof(MyGenericClass<,>)).Dump();

How would I determine in code that BobGeneric inherits from MyGenericClass ?

Answer 1

You're looking for GetGenericTypeDefinition :

typeof(BobGeneric).GetGenericTypeDefinition().IsSubclassOf(typeof(MyGenericClass<,>)).Dump();

You can imagine that method as "stripping away" all generic type arguments, just leaving the raw definition with its formal generic parameters.

If it does not work directly on BobGeneric , you may have to navigate upwards in the type hierarchy till you find MyGenericClass<...,...> (or any type for which IsGenericType returns true ).