本程序适用于并口(lpt端口)连接电脑的打印机,如果你的打印机是usb端口的,买一条 USB转并口线 即可.-This procedure applies to the parallel port (lpt port) to connect the computer' s printer, if your printer is usb port, buy a USB-parallel cable.

QT并口串口USB小票打印机操作，控件布局用的html-qt com and lpt printer