When you use FLTK with VS2010, you may get the error: fatal error C1083: Cannot open include file: ‘X11/Xlocale.h‘: No such file or directory.
The way to solve this is quite simple, just add the following line before ‘#include <FL/Fl.H>‘
#define WIN32
Solve error: Cannot open include file: 'X11/Xlocale.h': No such file or directory
原文：http://www.cnblogs.com/grandyang/p/5202588.html