1. Empty qmake Project

2, Qt Widgets

3. Layout

4. Menu bar

Two approaches to connecting slot and signal: 1) coding in mainwindow.cpp and 2) manually connecting signal (triggered) and slot in mainwindow.ui. (Icons can be downloaded at http://www.iconarchive.com/  )

5. Image Disaplay

6. Working with OpenCV

6. A simple app

Tips in building Qt projects: clean -> run qmake -> build -> run (try both debug and release mode)

Sources:

https://wiki.qt.io/Qt_Creator_Keyboard_Shortcuts

https://wiki.qt.io/Books