GetDiskFreeSpaceEx reports incorrect number of free bytes

Question

__int64 i64FreeBytes
unsigned __int64 lpFreeBytesAvailableToCaller,
                 lpTotalNumberOfBytes,
                 lpTotalNumberOfFreeBytes; // variables used to obtain 
                                           // the free space on the  drive

GetDiskFreeSpaceEx (Manager.capDir,
(PULARGE_INTEGER)&lpFreeBytesAvailableToCaller,
(PULARGE_INTEGER)&lpTotalNumberOfBytes,
(PULARGE_INTEGER)&lpTotalNumberOfFreeBytes);

i64FreeBytes = lpTotalNumberOfFreeBytes;
_tprintf(_T ("Number of bytes free on the drive:%I64u \n"),
     lpTotalNumberOfFreeBytes);

I am working on a data management routine, which is a Windows CE command-line application. The above code shows how I get the number of free bytes on a particular drive that contains the Manager.capdir folder (this is a variable containing the full path to the directory).

My question is that the number of free bytes transmitted by the above code (the _tprintf operator) does not match the number of free bytes of the disk (which I check by right-clicking on the disk).

I want to know if the reason for this difference is?

Answer 1

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Answer 2

( ) GetDiskFreeSpaceEx, :

lpFreeBytesAvailable [out, optional] -

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lpTotalNumberOfBytes [out, optional] -

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, IOCTL_DISK_GET_LENGTH_INFO.

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Answer 3

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