请教一下，如何得到一个USB设备的Path name，也就是用CreateFile函数打开时的第一个参数。谢谢了！

Question

请教一下，如何得到一个USB设备的Path name，也就是用CreateFile函数打开时的第一个参数。谢谢了！

Answer 1

http://www.vckbase.com/document/viewdoc/?id=1282

Answer 2

http://www.codeproject.com/w2k/usbdisks.asp

Answer 3

http://www.cppfans.com/articles/system/bcb_usb_a.asp

Answer 4

Result=SetupDiGetDeviceInterfaceDetail(
           hDevInfo,
           &devInfoData,
           NULL,
           0
           &Length
           NULL);
detailData=(PSP_DEVICE_INTERFACE_DETAIL_DATA)malloc(Length);
detailData->bSize=sizeof(PSP_DEVICE_INTERFACE_DETAIL_DATA);
Result=SetupDiGetDeviceInterfaceDetail(
           hDevInfo,
           &devInfoData,
           detailData,
           Length,
           &Required,
           NULL);

Answer 5

void CCCSUSBDlg::OnOpen() 
{
char *sInfo;
sInfo="正在查找系统中HID类的GUID标识...";
m_lbInfo.AddString(sInfo); GUID guidHID;
HidD_GetHidGuid(&guidHID); sInfo="->HID类的GUID标识为:";
m_lbInfo.AddString(sInfo); sprintf(sInfo,"%08x-%04x-%04x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x",
guidHID.Data1,
guidHID.Data2,
guidHID.Data3,
guidHID.Data4[0],guidHID.Data4[1],guidHID.Data4[2],guidHID.Data4[3],
guidHID.Data4[4],guidHID.Data4[5],guidHID.Data4[6],guidHID.Data4[7]);
m_lbInfo.AddString(sInfo); HDEVINFO hDevInfo = SetupDiGetClassDevs(&guidHID,
NULL,
0,
DIGCF_PRESENT|DIGCF_DEVICEINTERFACE ); if(hDevInfo==INVALID_HANDLE_VALUE)
{
sInfo="查找USB设备出错!";
m_lbInfo.AddString(sInfo);
return;
}
else
{
sInfo="找到USB设备!";
m_lbInfo.AddString(sInfo);
}
UINT nIndex = 0; sInfo= "正在查找可用的USB设备...";
m_lbInfo.AddString(sInfo); SP_DEVICE_INTERFACE_DATA InterfaceData; InterfaceData.cbSize=sizeof(SP_DEVICE_INTERFACE_DATA);
BOOL bSuccess;
DWORD index=0;
for(int i=0;i<10;i++)
{
bSuccess = SetupDiEnumDeviceInterfaces(hDevInfo,
  NULL,
  &guidHID,
  i,
  &InterfaceData);
if (!bSuccess)
{
sInfo="  连接USB设备出错!";
m_lbInfo.AddString(sInfo);
break;
}
else
{
if(InterfaceData.Flags==SPINT_ACTIVE )
{
sprintf(sInfo,"->连接 %d",index+1);
m_lbInfo.AddString(sInfo);
if(INVALID_HANDLE_VALUE!=GetUSBDeviceInfo(hDevInfo,InterfaceData) )
{
sInfo="  测试已完成!";
m_lbInfo.AddString(sInfo);
}
index++;
}
}
}
sprintf(sInfo,"总共%d个设备连接",index);
m_lbInfo.AddString(sInfo);
}HANDLE CCCSUSBDlg::GetUSBDeviceInfo(HDEVINFO hDevInfo, SP_DEVICE_INTERFACE_DATA InterfaceData)
{
char *sInfo;
PSP_DEVICE_INTERFACE_DETAIL_DATA pDetailData; DWORD dwSize=0,dwRequieSize=0;
SetupDiGetDeviceInterfaceDetail(hDevInfo,
&InterfaceData,
NULL,
0,
&dwSize,
NULL); dwRequieSize=dwSize;
pDetailData=(PSP_DEVICE_INTERFACE_DETAIL_DATA)malloc(dwRequieSize);
pDetailData->cbSize=sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA); //SP_DEVINFO_DATA InfoData;
//InfoData.cbSize=sizeof(SP_DEVINFO_DATA);
if (!SetupDiGetDeviceInterfaceDetail(hDevInfo,
 &InterfaceData,
 pDetailData,
 dwSize,
 &dwRequieSize,
 NULL))
{
sInfo="  查找设备路径时出错!";
m_lbInfo.AddString(sInfo);
//SetupDiDestroyDeviceInfoList(hDevInfo);
free(pDetailData);
}
char *sDevPath;
sDevPath=(pDetailData->DevicePath)+2;
*sDevPath='.';
sDevPath-=2;
sInfo="  设备路径:";
m_lbInfo.AddString(sInfo);
sInfo=sDevPath;
m_lbInfo.AddString(sInfo);
sInfo="  打开通信端口...";
m_lbInfo.AddString(sInfo); HANDLE hCom = CreateFile (sDevPath,
  GENERIC_READ | GENERIC_WRITE,
  FILE_SHARE_READ | FILE_SHARE_WRITE,
  NULL, 
  OPEN_EXISTING, 
  0, 
  NULL); if (hCom == INVALID_HANDLE_VALUE)
{
sInfo="  无法打开通信端口。不能读取设备信息!(设备连接可能不正确)";
m_lbInfo.AddString(sInfo);
free(pDetailData);
return hCom;
}
else
{
sInfo="  打开通信端口成功!";
m_lbInfo.AddString(sInfo); HIDD_ATTRIBUTES Attribute;
Attribute.Size=sizeof(HIDD_ATTRIBUTES); sInfo="  正在读取设备的标识...";
m_lbInfo.AddString(sInfo);

if(!HidD_GetAttributes(hCom,&Attribute))
{
sInfo="  查询设备状态时出错!";
m_lbInfo.AddString(sInfo);
//CloseHandle(hCom); free(pDetailData);
return INVALID_HANDLE_VALUE;
}
return hCom;
CloseHandle(hCom);
}
}

Answer 6

我用vc搞的这个程序，但是在bSuccess = SetupDiEnumDeviceInterfaces(hDevInfo,
  NULL,
  &guidHID,
  i,
  &InterfaceData);这里总是返回false请问是什么缘故？？谢谢