Getting List of Volumes always Says C:\

Why The Following Code always reports C:\ although It reports different Device Name

  handle = FindFirstVolumeW(volName, sizeof(volName));
  do{
    wchar_t wVolName[MAX_PATH];
    QString::fromWCharArray(volName).toWCharArray(wVolName);//make a copy of volName on wVolName
    wVolName[wcsle开发者_开发知识库n(volName)-1] = L'\0';
    wchar_t wDeviceName[MAX_PATH];
    int charCount = 0;
    charCount = QueryDosDeviceW(&wVolName[4], wDeviceName, ARRAYSIZE(wDeviceName));

    qDebug() << QString::fromWCharArray(wVolName) << "Device: " << QString::fromWCharArray(wDeviceName);//print wVolName and wDeviceName

    wchar_t driveName[MAX_PATH];
    GetVolumePathName(wDeviceName, driveName, MAX_PATH);
    CloseHandle(handle);

    qDebug() << QString::fromWCharArray(driveName);

  }while(FindNextVolume(handle, volName, sizeof(volName)));
  FindVolumeClose(handle);

Output:

"\\?\Volume{5c77cc58-d5ab-11e0-a0ec-806d6172696f}" Device:  "\Device\HarddiskVolume2" 
"C:\" 
"\\?\Volume{5c77cc59-d5ab-11e0-a0ec-806d6172696f}" Device:  "\Device\HarddiskVolume3" 
"C:\" 
"\\?\Volume{5c77cc57-d5ab-11e0-a0ec-806d6172696f}" Device:  "\Device\CdRom0" 
"C:\" 
"\\?\Volume{5c77cc56-d5ab-11e0-a0ec-806d6172696f}" Device:  "\Device\Floppy0" 
"C:\" 
"\\?\Volume{8d974f2c-e9a1-11e0-b7da-0013d407432f}" Device:  "\Device\Harddisk1\DP(1)0-    0+8" 
"C:\" 

Why doesn't it report D, E, etc ..

EDIT

and How can I derive the Drive Letter assigned to the Volume

The documentation for the function says it all:

You must specify a valid Win32 namespace path. If you specify an NT namespace path, for example, "\DosDevices\H:" or "\Device\HardDiskVolume6", the function returns the drive letter of the current volume, not the drive letter of that NT namespace path.

By the way, a volume can be mounted to multiple drive letters (a drive name like C: is nothing more than a symlink in the NT namespace), so it doesn't really make sense to translate in this manner.

From the GetVolumePathName documentation:

If you specify a relative directory or file name without a volume qualifier, GetVolumePathName returns the drive letter of the current volume.

Perhaps because you are calling CloseHandle while in the loop: don't do that.

It looks like you modeled your code after http://msdn.microsoft.com/en-us/library/cc542456%28v=vs.85%29.aspx: you'll notice the only time they call CloseHandle is AFTER the entire loop is done.