用这个：$$quote()
如何添加库？看下面添加mysql路径的例子:
INCLUDEPATH += $$quote(C:\Program Files (x86)\MySQL\MySQL Server 5.6\include)
LIBS += -L$$quote(C:\Program Files (x86)\MySQL\MySQL Server 5.6\lib) -llibmysql
http://blog.163.com/fafaly@126/blog/static/131693298201510353425223/