Why are so many old classes are dispeared in the new Qt lib?How can i deal with it?

[Dave2011]

I found there are so many code that used old classes Like the QVBox can't work.How can i deal with this problem?

[SixDegrees]

- Revert to version 3.x.

- Read the documentation. (http://doc.qt.nokia.com/latest/porting4.html)