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。

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#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;

}