感谢cmets。
经过一番挖掘，我发现this interesting article 使用usbprint.sys 提供的Windows 打印机功能。稍微修改一下示例代码似乎就可以了。我想我会走这条路。
有文中给出的最终代码：
/* Code to find the device path for a usbprint.sys controlled
* usb printer and print to it
*/
#include <usb.h>
#include <usbiodef.h>
#include <usbioctl.h>
#include <usbprint.h>
#include <setupapi.h>
#include <devguid.h>
#include <wdmguid.h>
/* This define is required so that the GUID_DEVINTERFACE_USBPRINT variable is
* declared an initialised as a static locally, since windows does not include it
* in any of its libraries
*/
#define SS_DEFINE_GUID(name, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
static const GUID name \
= { l, w1, w2, { b1, b2, b3, b4, b5, b6, b7, b8 } }
SS_DEFINE_GUID(GUID_DEVINTERFACE_USBPRINT, 0x28d78fad, 0x5a12, 0x11D1, 0xae,
0x5b, 0x00, 0x00, 0xf8, 0x03, 0xa8, 0xc2);
void SomeFunctionToWriteToUSB()
{
HDEVINFO devs;
DWORD devcount;
SP_DEVINFO_DATA devinfo;
SP_DEVICE_INTERFACE_DATA devinterface;
DWORD size;
GUID intfce;
PSP_DEVICE_INTERFACE_DETAIL_DATA interface_detail;
intfce = GUID_DEVINTERFACE_USBPRINT;
devs = SetupDiGetClassDevs(&intfce, 0, 0, DIGCF_PRESENT |
DIGCF_DEVICEINTERFACE);
if (devs == INVALID_HANDLE_VALUE) {
return;
}
devcount = 0;
devinterface.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
while (SetupDiEnumDeviceInterfaces(devs, 0, &intfce, devcount, &devinterface)) {
/* The following buffers would normally be malloced to he correct size
* but here we just declare them as large stack variables
* to make the code more readable
*/
char driverkey[2048];
char interfacename[2048];
char location[2048];
char description[2048];
/* If this is not the device we want, we would normally continue onto the
* next one or so something like
* if (!required_device) continue; would be added here
*/
devcount++;
size = 0;
/* See how large a buffer we require for the device interface details */
SetupDiGetDeviceInterfaceDetail(devs, &devinterface, 0, 0, &size, 0);
devinfo.cbSize = sizeof(SP_DEVINFO_DATA);
interface_detail = calloc(1, size);
if (interface_detail) {
interface_detail->cbSize = sizeof (SP_DEVICE_INTERFACE_DETAIL_DATA);
devinfo.cbSize = sizeof(SP_DEVINFO_DATA);
if (!SetupDiGetDeviceInterfaceDetail(devs, &devinterface, interface_detail,
size, 0, &devinfo)) {
free(interface_detail);
SetupDiDestroyDeviceInfoList(devs);
return;
}
/* Make a copy of the device path for later use */
strcpy(interfacename, interface_detail->DevicePath);
free(interface_detail);
/* And now fetch some useful registry entries */
size = sizeof(driverkey);
driverkey[0] = 0;
if (!SetupDiGetDeviceRegistryProperty(devs, &devinfo, SPDRP_DRIVER, &dataType,
(LPBYTE)driverkey, size, 0)) {
SetupDiDestroyDeviceInfoList(devs);
return;
}
size = sizeof(location);
location[0] = 0;
if (!SetupDiGetDeviceRegistryProperty(devs, &devinfo,
SPDRP_LOCATION_INFORMATION, &dataType,
(LPBYTE)location, size, 0)) {
SetupDiDestroyDeviceInfoList(devs);
return;
}
usbHandle = CreateFile(interfacename, GENERIC_WRITE, FILE_SHARE_READ,
NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL |
FILE_FLAG_SEQUENTIAL_SCAN, NULL);
if (usbHandle != INVALID_HANDLE_VALUE) {
/* Now perform all the writing to the device ie.
* while (some condition) WriteFile(usbHandle, buf, size, &bytes_written);
*/
CloseHandle(usbHandle);
}
}
}
SetupDiDestroyDeviceInfoList(devs);
}
再次感谢您的建议。