Opening USB device from application

odomae

Hi,

I am trying to open a USB mass storage device from a windows application. To use CreateFile(), I needed the device name. So I did the following.

hardwareDeviceInfo = SetupDiGetClassDevs(&UsbClassGuid,
NULL, // Define no enumerator (global)
NULL, // Define no
DIGCF_PRESENT| DIGCF_DEVICEINTERFACE // Only Devices present
); // Function class devices.
if (hardwareDeviceInfo == INVALID_HANDLE_VALUE)
{
return INVALID_HANDLE_VALUE;
}
else
printf(" SetupDiGetClassDevs returned a valid handle!\n");

//Get Device Interface Data
deviceInterfaceData.cbSize = sizeof(deviceInterfaceData);
(SetupDiEnumDeviceInterfaces(hardwareDeviceInfo, NULL, &UsbClassGuid, 0, &deviceInterfaceData))


The call to SetupDiEnumDeviceInterfaces() fails.

Any ideas on what the problem could be?

I got the USB GUID from the windows system defined GUID list for disk drives.

Odomae