回帖：可以参考的文档
http://doc-snapshot.qt-project.org/qt5-stable/qtdoc/portingcppapp.html
http://doc-snapshot.qt-project.org/qt5-stable/qtdoc/obsoleteclasses.html
http://doc-snapshot.qt-project.org/qt5-stable/qtdoc/sourcebreaks.html
http://www.kdab.com/porting-from-qt-4-to-qt-5/
http://www.kdab.com/automated-porting-from-qt-4-to-qt-5/
http://blog.qt.digia.com/cn/2012/07/09/porting-from-qt-4-to-qt-5/