about Memory-Mapped Files do with the big file.

[lxlenovostar]

i have wirtten a demo, which i want to chip the big file into the small ones by Memory-Mapped Files. the main code: HANDLE hFile = CreateFile(filePathName, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); HANDLE hFileMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL); pvFile = MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, dwCurPart); HANDLE hNewFile = CreateFile(fileName, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); HANDLE hNewFileMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, dwCurPart, NULL); PVOID pvNewFile = MapViewOfFile(hNewFileMap, FILE_MAP_WRITE, 0, 0, 0); memcpy(pvNewFile, pvFile, dwCurPart); i can get the new files,but the file don't get any content.i think the "memcpy();" can let the content copy into the new files. thanks for your help.

[_Superman_]

You have set the dwNumberOfBytesToMap parameter for the destination file to 0. Memory mapped files cannot grow like a disk files. You have to create the destination file with blanks and set the dwNumberOfBytesToMap to the desired number of bytes. To create a blank file use SetEndOfFile after the CreateFile call.

«_Superman_»
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Polymorphism in C

modified on Tuesday, May 25, 2010 12:09 PM