c# - Compile-time information lost with conversion to object, cannot cast to generic interface<T> -

i have class implementing concrete typed version of generic interface. have found if pass object in function (even though might correct object) @ compile time still considered object , failing @ runtime error:

unable cast object of type 'testeventhandler' type 'idomaineventhandler '1[system.object]'.

i deserializing messages bus (which products objects, should have associated domaineventhandler<of_deserialized_type> associated message.

in summary, problem believe idomaineventhandler<t> not casting `idomaineventhandler<object>, appreciate guidance on how best solve issue , still maintain generic idomaineventhandler<t> interface objects being passed in publish().

[testclass] public class internalmessagehandlertests {     class testevent     {     }      class testeventhandler : idomaineventhandler<testevent>     {         public void handleevent(testevent domainevent)         {         }     }      [testmethod]     public void test()     {         testevent testevent = new testevent();         object testeventasobject = testevent; // compile time type information lost          publish(testevent); // ok :)         publish(testeventasobject); // fails :(      }      public void publish<t>(t eventtopublish) t : class     {         var handlerinstance = new testeventhandler();         idomaineventhandler<t> converted = (idomaineventhandler<t>)handlerinstance;         converted.handleevent(eventtopublish);     } } 

in situation, not possible support fully-generic interface without reflection. , reflection pretty bad idea such simple case.

my normal approach these situations idomaineventhandler, domaineventhandlerbase<t> : idomaineventhandler inheriting classes advantage of generics, outside interface can accept objects.

obviously not statically safe, said not possible statically safe here. assigned instance object testeventasobject, made possible variable contain compiler point of view (string, int, anything).

for things service bus have select right handler, this:

public interface idomaineventhandler {     void handleevent(object domainevent);     bool canhandleevent(object domainevent); }  public abstract class domaineventhandlerbase<t> : idomaineventhandler {     public abstract void handleevent(t domainevent);     public abstract bool canhandleevent(t domainevent);      void idomaineventhandler.handleevent(object domainevent) {         return handleevent((t)domainevent);     }      bool idomaineventhandler.canhandleevent(object domainevent) {                     return (domainevent t) && canhandleevent((t)domainevent);     } } 

i has written directly (without checking in vs) mistakes possible.

after when receive message select

handlers.first(h => h.canhandleevent(domainevent))