本文介绍如何使用CreateFileMapping,MapViewOfFile创建内存映射文件，如何向内存映射文件中写入数据，读取数据。

#include <iostream>  #include <assert.h>    #include <Windows.h>  #include <WinBase.h>    #define BAD_POS 0xFFFFFFFF // returned by SetFilePointer and GetFileSize  #define SUCCESS 0  using namespace std;    typedef DWORD mmf_share_mode;  typedef DWORD mmf_access_mode;  typedef DWORD mmf_flags;    int main(){      cout<<"create memorymapfile..."<<endl;      const char* shared_name = "testMmf";      const char* file_name = "d:\\testMmf.mmf";      const DWORD mmf_size = 512*1024;      //存取模式      mmf_access_mode access_mode = (GENERIC_READ|GENERIC_WRITE);      //共享模式      mmf_share_mode share_mode = FILE_SHARE_READ | FILE_SHARE_WRITE;      //文件属性      mmf_flags flags = FILE_FLAG_SEQUENTIAL_SCAN;//|FILE_FLAG_WRITE_THROUGH|FILE_FLAG_NO_BUFFERING;      DWORD error_code;        //创建文件      HANDLE mmHandle =          CreateFile(file_name,               access_mode,                share_mode,                NULL,                OPEN_ALWAYS,               flags,               NULL);        if (mmHandle == INVALID_HANDLE_VALUE) {          error_code = GetLastError();          cout<<"创建mmf失败:"<<error_code<<endl;      }else{          DWORD high_size;          DWORD file_size = GetFileSize(mmHandle, &high_size);          if (file_size == BAD_POS && (error_code = GetLastError()) != SUCCESS) {              CloseHandle(mmHandle);                          cout<<"error："<<error_code<<endl;          }          cout<<"create mmf sucessfully"<<endl;            //assert(file_size == 0);            DWORD size_high = 0;          //创建文件映射，如果要创建内存页面文件的映射，第一个参数设置为INVALID_HANDLE_VALUE          HANDLE mmfm = CreateFileMapping(mmHandle,              NULL,              PAGE_READWRITE,              size_high,               mmf_size,               shared_name);            error_code = GetLastError();          if(SUCCESS != error_code){              cout<<"createFileMapping error"<<error_code<<endl;          }else{              if(mmfm == NULL){                  if(mmHandle != INVALID_HANDLE_VALUE){                      CloseHandle(mmHandle);                  }              }else{                  //char write_chars[] = "hello chars";                  //size_t position = 0;                  //DWORD written = 0;                  //const size_t write_chars_size = sizeof(write_chars);                  //WriteFile(mmHandle,write_chars,write_chars_size,&written,NULL);                  size_t view_size = 1024*256;                  DWORD view_access = FILE_MAP_ALL_ACCESS;                    //获得映射视图                  char* mmfm_base_address = (char*)MapViewOfFile(mmfm,view_access,0,0,view_size);                  if(mmfm_base_address == NULL){                      error_code = GetLastError();                      if(error_code != SUCCESS){                          cout<<"error code "<<error_code<<endl;                      }                  }else{                      char write_chars[] = "hello chars";                      const size_t write_chars_size = sizeof(write_chars);                      //向内存映射视图中写数据                      CopyMemory((PVOID)mmfm_base_address, write_chars, write_chars_size);                        //memcpy(mmfm_base_address,write_chars,write_chars_size);                        size_t position = 0;                      char read_chars[write_chars_size];                        //读数据                      memcpy(read_chars,mmfm_base_address,write_chars_size);                      cout<<"read chars "<<read_chars<<endl;                        //卸载映射                      UnmapViewOfFile(mmfm_base_address);                      //关闭内存映射文件                      CloseHandle(mmfm);                      //关闭文件                      CloseHandle(mmHandle);                  }              }          }      }        system("pause");      exit(0);      return EXIT_SUCCESS;  }