struct USB_DESCRIPTOR_REQUEST

Structure USB_DESCRIPTOR_REQUEST

The USB_DESCRIPTOR_REQUEST structure is always followed by either a USB_STRING_DESCRIPTOR or USB_DEVICE_DESCRIPTOR structure.

typedef struct _USB_DESCRIPTOR_REQUEST {

} USB_DESCRIPTOR_REQUEST, *PUSB_DESCRIPTOR_REQUEST

   USB_DESCRIPTOR_REQUEST Request = new USB_DESCRIPTOR_REQUEST();

You don't use an IOCTL call directly with a USB_STRING_DESCRIPTOR structure. Instead you use a USB_DESCRIPTOR_REQUEST "request packet" with IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION. The USB_STRING_DESCRIPTOR structure is returned at the very end of the request packet. The whole idea of "writing off the edge" of a structure is counter to the way C#/VB.Net was designed to work, so you'll have to make sure to allocate sufficient amount of memory to handle both the "request packet" and the USB_STRING_DESCRIPTOR structure.

   USB_DESCRIPTOR_REQUEST Request = new USB_DESCRIPTOR_REQUEST();