设计一个keypad UI 然后通过windows API调用一个ＵＳＢ软件，达到控制投影机的功能，UI做的非常的好，如果想做QT界面可以好好看看。-Design a keypad UI and then through a USB software windows API call, to control the projector function, UI do very well, if you want to do QT interface can have a good look.