创建指定大小的文件

方法一：

#include <windows.h>void main(){int size = 24;//24个字节HANDLE hFile = CreateFile("test.dat", GENERIC_WRITE|GENERIC_READ, FILE_SHARE_READ, 0, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);HANDLE hMap = CreateFileMapping(hFile, 0, PAGE_READWRITE, 0, size, 0);//指定大小，文件将以0填充void* pMap = MapViewOfFile(hMap, FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, 0);UnmapViewOfFile(pMap);CloseHandle(hMap);CloseHandle(hFile);}

方法二：

#include <windows.h>void main(){int lDistance = 10240;HANDLE hFile = CreateFile("test2.dat", GENERIC_WRITE|GENERIC_READ, FILE_SHARE_READ, 0, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);SetFilePointer (hFile, lDistance, NULL, FILE_BEGIN) ;SetEndOfFile(hFile);//必须调用SetEndOfFile，否则SetFilePointer的修改不生效CloseHandle(hFile);}

两种方法会用0填充满文件，得到的并不是稀疏文件。