Compiler Error C3731

incompatible event 'function1' and handler 'function2'; event source and event handler must be the same type

Remarks

The event source and event receiver must have the same type (for example native vs. com types). To fix this error, make the types of the event source and the event handler match.

Example

The following example generates C3731:

// C3731.cpp
// compile with: /clr
#using <mscorlib.dll>
[event_source(native)]
struct A {
   __event void MyEvent();
};

[event_receiver(managed)]
// try the following line instead
// [event_receiver(native)]
struct B {
   void func();
   B(A a) {
      __hook(&A::MyEvent, &a, &B::func);   // C3731
   }
};

int main() {
}