http://board.flatassembler.net/viewtopic.php?t=1558

Hello, just a quick question: does anyone know how to determine the size of a file mapping object if only given the handle (returned by CreateFileMapping)? I want to know for when allocating a DIB section through a file mapping object (using CreateDIBSection). Thanks
--Chorus

Try to use GlobalSize function. I have not enough time to test it but i guess it works.

Под NT+ наверное можно ZwQuerySection(Handle, SectionBasicInformation,...)

Вернется

typedef struct _SECTION_BASIC_INFORMATION {
PVOID BaseAddress;
ULONG Attributes;
LARGE_INTEGER Size;
} SECTION_BASIC_INFORMATION,*PSECTION_BASIC_INFORMATION;