c++共享内存操作实例

  

1、创建共享内存 

       HANDLE hMapping;

LPTRANSDATA lpData;   //要发送的结构体
hMapping = CreateFileMapping(INVALID_HANDLE_VALUE,NULL,PAGE_READWRITE,0,1024,SHAREMEM_CMD_SEND);

if (hMapping != NULL)
{
lpData = (LPTRANSDATA)MapViewOfFile(hMapping,FILE_MAP_ALL_ACCESS,0,0,0);
if (lpData == NULL)
{
CloseHandle(hMapping);
hMapping = NULL;
AfxMessageBox("MapViewOfFile() failed.");
return;
}
}
else
{
AfxMessageBox("CreateFileMapping() failed.");
return;
}
CopyMemory(lpData,lpMsg,sizeof(LPTRANSDATA));

2、打开创建的映射文件

         HANDLE hMapping;
hMapping = OpenFileMapping(FILE_MAP_READ,FALSE,SHAREMEM_CMD_SEND);
if (hMapping == NULL)
{
MessageBox("hMapping == NULL");
return NULL;
}
transData = (LPTRANSDATA)MapViewOfFile(hMapping,FILE_MAP_READ,0,0,0);
if (transData == NULL)
{
CloseHandle(hMapping);
MessageBox("str == NULL");
return NULL;
}

if (transData  != NULL)
{
UnmapViewOfFile(transData );
transData = NULL;
}
if (hMapping != NULL)
{
CloseHandle(hMapping);
hMapping = NULL;

}