must #include <windows.h> to use multi-threading with events
The windows.h file is required if you use multi-threading with events. To fix this error, add #include <windows.h>
to the top of the file in which event sources and event receivers are defined.
// uncomment the following line to resolve // #include <windows.h> [event_source(native), threading(apartment)] class CEventSrc { public: __event void event1(); // C3724 }; [event_receiver(native)] class CEventRec { public: void handler1() { } void HookEvents(CEventSrc* pSrc) { __hook(CEventSrc::event1, pSrc, CEventRec::handler1); } void UnhookEvents(CEventSrc* pSrc) { __unhook(CEventSrc::event1, pSrc, CEventRec::handler1); } }; void main() { }