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标题: USB HID设备读写代码实现c++（4） [打印本页]

作者: yuyang911220 时间: 2015-12-24 21:59 标题: USB HID设备读写代码实现c++（4）

bool MCDHid::findMCDHid()
{
int vendorID = VENDOR_ID;
int productID = PRODUCT_ID;
DWORD required;
GUID hidGuid;
HDEVINFO hDevInfo;
SP_DEVICE_INTERFACE_DATA devInfoData;
int memberIndex = 0;
LONG result;
bool lastDevice = false;
DWORD length;
PSP_DEVICE_INTERFACE_DETAIL_DATA detailData = NULL;
bool deviceDetected = false;

HidD_GetHidGuid(&hidGuid);
hDevInfo = SetupDiGetClassDevs
   (&hidGuid,
   NULL,
   NULL,
   DIGCF_PRESENT|DIGCF_INTERFACEDEVICE);
//当应用程序不再需要使用SetupDiGetClassDevs函数的传回值hDevInfo所指的数组时，应该调用SetupDiDeStroyDeviceInfoList函数来释放资源
if(hDevInfo == INVALID_HANDLE_VALUE)
{
   //printf("Failed to open device handle!");
   return false;
}

devInfoData.cbSize = sizeof(devInfoData);
do
  {
result = SetupDiEnumDeviceInterfaces(
   hDevInfo,
   0,
   &hidGuid,
   memberIndex,
   &devInfoData);
if (result != 0)
{
result = SetupDiGetDeviceInterfaceDetail(
      hDevInfo,
      &devInfoData,
      NULL,
      0,
      &length,
      NULL);
detailData = (PSP_DEVICE_INTERFACE_DETAIL_DATA)malloc(length);
if(!detailData)
            {
            //printf("Device information allacation failed!");
            return false;
            }
detailData -> cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
result = SetupDiGetDeviceInterfaceDetail(
      hDevInfo,
      &devInfoData,
      detailData,
      length,
      &required,
      NULL);
if(!result)
            {
            //printf("Device information reallocation failed!");
            return false;
            }
_hidDevice.HidDevice = CreateFile(
      detailData->DevicePath,
      GENERIC_READ|GENERIC_WRITE,
      FILE_SHARE_READ|FILE_SHARE_WRITE,
      (LPSECURITY_ATTRIBUTES)NULL,
      OPEN_EXISTING,
      FILE_FLAG_OVERLAPPED,
      NULL);

_hidDevice.Attributes.Size = sizeof(HIDD_ATTRIBUTES);
result = HidD_GetAttributes(
      _hidDevice.HidDevice,
      &_hidDevice.Attributes);
if ((_hidDevice.Attributes.VendorID == vendorID) && (_hidDevice.Attributes.ProductID == productID))
         {
            int status;
            PHIDP_PREPARSED_DATA PreparsedData ;
            deviceDetected = true;

            //获取USB设备的预解析数据
            result = HidD_GetPreparsedData(_hidDevice.HidDevice,&PreparsedData);
            if(!result)
            {
            //printf("无法获取USB设备的预解析数据!");
            return false;
            }
            status= HidP_GetCaps(PreparsedData, &_hidDevice.Caps);
   _fUsbCommRunning = true;
   HidD_FreePreparsedData(PreparsedData);
   PreparsedData = NULL;

}
else
{
   //printf("没有找到设备!");
   closeMCDHid();
}
free(detailData);
detailData = NULL;
}
else
{
         lastDevice = true;
}
memberIndex = memberIndex + 1;
  }while((lastDevice == false)&&(deviceDetected == false));

  SetupDiDestroyDeviceInfoList(hDevInfo);
  return deviceDetected;
}

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