Useful resources
Still getting stuck with an issue? In addition to online search engines, there are two online forums that could also be useful for you. The first one is the forum in the Qt Project, whose URL is http://qt-project.org/forums. The other one is maintained by a community site, Qt Centre, and its URL is http://www.qtcentre.org/forum.php.
In most cases, you should be able to find similar or even identical problems on these websites. If not, you can post a new thread asking for help. Describe the problem as thoroughly as possible so that other users can get an idea of what's going wrong.
There is a possibility that you did everything correctly but still might be getting unexpected results, compiler errors, or crashes. In this case, it may be a Qt bug. If you believe that you've encountered a Qt bug, you are encouraged to report it. It's easy to report a bug since Qt has a bug tracker, whose URL is https://bugreports.qt.io.
Tip
The quality of the bug report dramatically...