Mouse events (QMouseEvent): Press release, move
QEvent: enter, leave
Keyboard events (QKeyEvent): Press the keyboard
Timer events (QTimerEvent): open, stop
New Qt Widgets Application project, Base class selection QWidget, class name MyWidget
Add two label interface
Create mylabel class, temporarily inherited from QWidget (because there is no QLabel option), then h and cpp files into QLabel.
Interface label, the right mouse button - promoted , so QLabel class becomes class custom mylabel
The reason why the control class, in order to achieve some customized features. achieve the label mouse events, QEvent they enter and leave events
The timer event QWidget, the display on the label, label_2. Source download
