Qt Reference Pages
If you know the name of the class you want, find it here.
If you don't know the name of the class you want, but you know what the class should do, you might try looking here.
If you know what kind of class you want (GUI, painting, I.O, etc), look here.
The C++ class inheritance hierarchy for all classes in the Qt API.
These classes are obsolete and should not be used in new code.
A Qt namespace contains enum types, functions, and sometimes classes.
A list of all C++ modules in Qt 5
A list of all QML API in Qt 5
Qt 5 consists of essential modules, add-on modules, and tools.
All documented Qt functions listed alphabetically with a link to where each one is declared.
Exported functions for fine tuning Qt applications.