It seems worse that POCO may not work in Metro App nor compiled when referenced in the source codes of a Metro App.
When I add some POCO's header files to a .cpp file of a Metro App, compiler reported error that some Win32 API can't be resolved.
The Metro App project is based on a Metro App sample "Hybird app DLL server authoring sample". Then I added all headers listed in the "download.cpp" sample of POCO's NET and invoked HTTPStreamFactory::registerFactory() method in the Toast::RuntimeClassInitialize method. However, errors were reported when compiling. The first one is "error C2027: use of undefined type 'Poco::Net::in_addr'" in the header file "ipaddress.h".
How to make POCO work in Metro App? As a platform independent powerful component, POCO should think of the new coming OS and the new type of application "Metro Style Application".