自动通过系统信息检测当前插入的USB设备打印机，并通过USB端口发送数据打印-Detected automatically by the system information inserted USB device printer through the USB port to send data printing

usb打印机的端口定位,本程序通过遍历设备找到USB打印机，根据注册表确定端口与状态-usb printer port positioning this program find a USB printer by traversing devices , according to the registry to determine the port and status