Compiler Error C3707

'function' : dispinterface method must have a dispid

If you use a dispinterface method, you must assign it a dispid. To fix this error, assign a dispid to the dispinterface method, for example, by uncommenting the id attribute on the method in the sample below. For more information, see the attributes dispinterface and id.

The following sample generates C3707:

// C3707.cpp
#include <atlbase.h>
#include <atlcom.h>
#include <atlctl.h>

__interface IEvents : IDispatch
   HRESULT event1([in] int i);   // C3707
   // try the following line instead
   // [id(1)] HRESULT event1([in] int i);

int main() {