c# - IndexOutOfRangeException when trying to access the generic arguments of a Func<object> delegate -

i need generic argument type factory delegate (func<object), results in indexoutofrangeexception.

public void bind(type service, func<object> factory) {     var factoryresulttype = factory.method.getgenericarguments()[0]; // ex }  // extension public static void bind<tservice>(this ibinder binder, func<tservice> factory)     tservice : class  {     binder.bind(typeof(tservice), (func<object>) factory); }  // usage var dummyclass = new dummyclass(); binder.bind<idummy>(() => dummyclass); 

a delegate func<t> compiled along these lines:

public class func<t> {     public t invoke() { /* ... */ } } 

the methodinfo returned factory.method represents invoke method above. can see, method not generic, , that's why code fails.

you could, instead, check return type:

var type = f.method.returntype; 

or, @sszarek suggested, check type's generic arguments.