解决办法:
1. Do not use the /mktyplib203 switch unless you have to deal with legacy code dating back to mktyplib ver.2.03.
2. In the .odl file, put the following inside the library block:
#include <olectl.h>
参考资料:
https://social.msdn.microsoft.com/Forums/en-US/5ae2ed97-66cc-4dd8-ad88-4245f93d7628/error-midl2311-statements-outside-library-block-are-illegal-in-mktyplib-compatability-mode?forum=vcgeneral