Question

I got a generic Interface like this :

public interface IResourceDataType<T>
{
    void SetResourceValue(T resValue);
}

Then I got this class that implements my Interface :

public class MyFont : IResourceDataType<System.Drawing.Font>
{
    //Ctor + SetResourceValue + ...
}

And finally I got a :

var MyType = typeof(MyFont);

I, now, want to get the System.Drawing.Font Type from MyType !
At the moment, I got this code :

if (typeof(IResourceDataType).IsAssignableFrom(MyType))
{
    //If test is OK
}

But I don’t manage to “extract” my Type here…
I tried a couple of things with GetGenericArguments() and other things but they either don’t compile or return a null value/List…
What do I have to do ?

EDIT :
Here is the solution that fit my code for those who will get the same problem :

if (typeof(IResourceDataType).IsAssignableFrom(MyType))
{
    foreach (Type type in MyType.GetInterfaces())
    {
        if (type.IsGenericType)
            Type genericType = type.GetGenericArguments()[0];
        }
    }
}

Answer 1

Since your MyFont class only implements one interface, you can write:

Type myType = typeof(MyFont).GetInterfaces()[0].GetGenericArguments()[0];

If your class implements several interfaces, you can call the GetInterface() method with the mangled name of the interface you’re looking for:

Type myType = typeof(MyFont).GetInterface("IResourceDataType`1")
                            .GetGenericArguments()[0];