Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct
About Qt help documents
Recently I install QT5, and there is only Qt Creator Manual in the help documents, how can I get all QT reference like QT C++ classes, QT QML APIs and so on?
in your clone of Qt repo. If you have installed the SDK, then the help should be already build. Look for it in <qtdir>/qtdocs/ (IIRC. Could be in qtbase, too).
How did you install Qt 5? How did you install Qt Creator?
I found that when I build from Git, I need to build the qttools.git repo before calling `make docs'. Otherwise, Qt Creator Help files won't build (last tested in early Feb 2013)
I build it from ubuntu app developer: http://developer.ubuntu.com/get-started/gomobile/
sudo add-apt-repository ppa:canonical-qt5-edgers/qt5-proper && sudo add-apt-repository ppa:ubuntu-sdk-team/ppa && sudo apt-get update && sudo apt-get install ubuntu-sdk notepad-qml
I re-install QT5 from .run file of QT official site, it is Ok now, thanks.