本帖最后由 liuqiong023 于 2020-8-31 17:14 编辑
大家好，我想问一个USB hid的问题。
如果我的USB设备是单描述符，下面的代码是可以的。
但是如果我USB设备时双描述符， 下面的代码只能获取到第一个descriptor的值，但是获取不到第二个descriiptor的值。
GUID hidGuid; /* GUID for HID driver */
HDEVINFO deviceInfoList;
SP_DEVICE_INTERFACE_DATA deviceInfo;
SP_DEVICE_INTERFACE_DETAIL_DATA *deviceDetails = NULL;
DWORD size;
int i, openFlag = 0; /* may be FILE_FLAG_OVERLAPPED */
int errorCode = USBOPEN_ERR_NOTFOUND;
HANDLE handle = INVALID_HANDLE_VALUE;
HIDD_ATTRIBUTES deviceAttributes;
HidD_GetHidGuid(&hidGuid);
deviceInfoList = SetupDiGetClassDevs(&hidGuid, NULL, NULL, DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);
deviceInfo.cbSize = sizeof(deviceInfo);
for(i=0;; i++) {
if(handle != INVALID_HANDLE_VALUE) {
CloseHandle(handle);
handle = INVALID_HANDLE_VALUE;
}
if(!SetupDiEnumDeviceInterfaces(deviceInfoList, 0, &hidGuid, i, &deviceInfo))
break; /* no more entries */
/* first do a dummy call just to determine the actual size required */
SetupDiGetDeviceInterfaceDetail(deviceInfoList, &deviceInfo, NULL, 0, &size, NULL);
if(deviceDetails != NULL)
free(deviceDetails);
deviceDetails = malloc(size);
deviceDetails->cbSize = sizeof(*deviceDetails);
/* this call is for real: */
SetupDiGetDeviceInterfaceDetail(deviceInfoList, &deviceInfo, deviceDetails, size, &size, NULL);
DEBUG_PRINT(("checking HID path \"%s\"\n", deviceDetails->DevicePath));
/* attempt opening for R/W -- we don't care about devices which can't be accessed */
handle = CreateFile(deviceDetails->DevicePath, GENERIC_READ|GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, openFlag, NULL);
if(handle != INVALID_HANDLE_VALUE) {
if (!HidD_GetPreparsedData(handle ,&PreparsedData))
{
//doing
}
if(!HidP_GetCaps(PreparsedData,&Capabilities))
{
//doing
}
}
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