CreateFileMapping_1

#include <Windows.h>#include <tchar.h>int WINAPI _tWinMain(HINSTANCE hinstance, HINSTANCE,    PTSTR pszCmdLine, int nCmdShow){    // Before executing the line below, C:\ does not have a file called "test.dat"    // 失败后返回INVALID_HANDLE_VALUE(定义为-1),    HANDLE hFile = CreateFile(_T("C:\\test.dat"), GENERIC_READ | GENERIC_WRITE,        FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_ALWAYS,        FILE_ATTRIBUTE_NORMAL, NULL);    // Before executing the line below, the test.dat file does exist but has a file size of 0 bytes.    // 失败后返回NULL    HANDLE hFileMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 100, NULL);    // After executing the line above, the test.dat file has a size of 100 bytes.    // cleanup    CloseHandle(hFileMap);    CloseHandle(hFile);    // code1    //HANDLE hFileMapping = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL);    //DWORD dwFileSizeHigh;    //__int64 qwFileSize = GetFileSize(hFile, &dwFileSizeHigh);    //char addMsg[] = { "test" };    //__int64 myFileSize = qwFileSize + sinf.dwAllocationGranularity;    //HANDLE hMyFileMap = CreateFileMapping(hmyFile, NULL, PAGE_READWRITE,        //(DWORD)(myFileSize >> 32), (DWORD)(myFileSize & 0xffffffff), NULL);    // When the process terminates, test.dat remians on the disk with a size of 100 bytes.    return 0;}