一个通用定时器类，可用于无窗口类中。本例程使用一个C++类，利用定时器变换指示灯。程序中用到：自定义的定时器类、C++多类继承、使用纯虚函数的中间类、指示灯变换设置。,A general-purpose timer class can be used for non-window class. The routine use of a C++ classes, the use of timer indicator transform. Programs used: a custom timer

QLed Indicator custom Qt Designer plugin