C++使用旋转按钮的实例源码，也就是在普通输入框的旁边加入了递增、递减的功能，点击上下不同的小三角，数值会增加或减少，步长为1，当然步长大小是可以自定义的，一般默认是1。-C++ using the rotate button instance source, that is, in the ordinary input box next to join the increment, decrement function, click the up and down the small triangle, the value will increase or reduce, in steps of 1, of course, the step size is can be self-defined, default is 1.