在服务和应用程序之间共享内存，应用程序不能创建共享内存块，请大家帮忙，附代码

Javpp 2004-11-13 08:51:52

已经把服务设置为允许与桌面交互，如果先在应用程序中创建共享内存，然后启动服务，通讯没问题，但是如果先启动服务的，再启动应用程序创建共享内存，那么在CreateFileMapping中就会返回错误，无法创建，请高手指点

另：
服务的代码和变量
//---------------------------------------------------------------------------
HANDLE hShareMemoryFile;
LPCTSTR strShareMemName;
LPVOID lpData;
void __fastcall TService1::ServiceExecute(TService *Sender)
{
while (!Terminated)
{
strShareMemName = "MyShareMemName";

hShareMemoryFile = CreateFileMapping (
(HANDLE) 0xFFFFFFFF,
NULL,
PAGE_READWRITE,
0,
1024,
strShareMemName
);

if (!hShareMemoryFile)
{
ShowMessage ("faile");
return;
}
else if(GetLastError () == ERROR_ALREADY_EXISTS)
{
//ShowMessage ("already exists");
//return;
}

lpData = MapViewOfFile (
hShareMemoryFile,
FILE_MAP_ALL_ACCESS,
0,
0,
0
);

if (lpData == NULL)
{
ShowMessage ("MapViewOfFile () failed");
return;
}
memset (lpData, 0, 1024);
memcpy (lpData, "hello", 1024);
Sleep (1000);
ServiceThread->ProcessRequests (false);
}
}
//---------------------------------------------------------------------------

应用程序的代码

HANDLE hShareMemoryFile;
LPCTSTR strShareMemName;
LPVOID lpData;
char tmp[1024];

//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)
{
//WM_RECEIVEDATAMSG = RegisterWindowMessage (SHAREDATA);
strShareMemName = "MyShareMemName";

hShareMemoryFile = CreateFileMapping (
(HANDLE) 0xFFFFFFFF,
NULL,
PAGE_READWRITE,
0,
1024,
strShareMemName
);

if (!hShareMemoryFile)
{
ShowMessage ("faile");
return;
}
else if(GetLastError () == ERROR_ALREADY_EXISTS)
{
//ShowMessage ("already exists");
//return;
}

lpData = MapViewOfFile (
hShareMemoryFile,
FILE_MAP_ALL_ACCESS,
0,
0,
0
);

if (lpData == NULL)
{
ShowMessage ("MapViewOfFile () failed");
return;
}

memcpy (tmp, lpData, 1024);

Memo1->Text = "";
Memo1->Text = tmp;
}
//---------------------------------------------------------------------------

...全文