Qt library link errors in Windows

mydialog.obj:-1: error: LNK2001: unresolved external symbol "struct QMetaObject const MyLibrary::staticMetaObject" (?staticMetaObject@MyLibrary@@3UQMetaObject@@B)

QMetaEnum myEnum = QMetaEnum::fromType<MyLibrary::MyEnumClass>();

namespace MyLibrary
{ 
Q_NAMESPACE 

enum class MYLIBRARYSHARED_EXPORT MyEnumClass
{
...
}; 

Q_ENUM_NS(MyEnumClass)

...
} // namespace MyLibrary