From: Пётр Косаревский<[EMAIL PROTECTED]>
To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org>
Subject: Re[2]: [fpc-pascal] Code example needed, please!
> I have code only with window messages and shared memory (if you don't want
> it, tell; otherwise I'll post some about an hour later).
I used something like that for shared memory in Delphi
ShMemFile is THandle, ShMemBuf is Pointer.
ShMemFile := CreateFileMapping(
INVALID_HANDLE_VALUE, <-- this creates file somewhere in
memory or swapfile
nil,
PAGE_READWRITE,
0,
ShMemSize, <-- set what you need
ShMemName); <-- this name will be used by the backend too!!
try to make it unique string, you can set it as command line parameter for
backend
if (ShMemFile=0) or (ShMemFile=INVALID_HANDLE_VALUE) then
begin Application.MessageBox('Shared memory error 1.','Internal
error',MB_OK); Close(); end;
ShMemBuf := MapViewOfFile(ShMemFile, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if (ShMemBuf=nil) then
begin Application.MessageBox('Shared memory error 2.','Internal
error',MB_OK); CloseHandle(ShMemFile); Close(); end;
{}
ShMemP:=ShMemBuf;
Where ShMemP is pointer to array[0..ShMemSize-1] of byte, so that you can
address bytes as ShMemP^[x] (somewhat lame).
And in the backend:
The types of ShMemFile and ShMemBuf are as in Delphi
ShMemFile := OpenFileMapping(
FILE_MAP_ALL_ACCESS,
false,
ShMemName);
if (ShMemFile=0) or (ShMemFile=INVALID_HANDLE_VALUE) then
begin writeln('File open failed!'); ASS_BACK(MsgFileReady); end;
ShMemBuf := MapViewOfFile(ShMemFile, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if ShMemBuf=nil then
begin writeln('File open failed!'); ASS_BACK(MsgFileReady); end;
ShMemBytes:=ShMemBuf;
Where ShMemBytes is byte pointer (so you address bytes as ShMemBytes[x]).
This code creates one chunk of shared memory of ShMemSize size. I used about
64K. Probably, anything up to gigabyte will work, but may be slow.
All these functions are described in MSDN, the only thing not nice is that you
have to guess some default values and pascal types (it's the same in Delphi
help: the examples are in C, if I remember right).
If you plan sending window messages, I can send some working code (ask). There
are examples (for Delphi) in internet on sites like
http://delphi.about.com/od/windowsshellapi/l/aa093003a.htm.
Of course, all the functions are described in MSDN.
There are simple hints: the window handle is Application.handle (you can send
it to backend, so that the dialog will not be broadcast from the beginning,
also you have to write message hookers in both programs [and create dummy
window in FPC one], if you want them to not freeze for some time, use the
functions windows.peekmessage, windows.postmessage, windows.translatemessage,
windows.dispatchmessage; if I remember right, one of them could have name
conflict with something in another unit).
If you want some little fun, broadcast WM_KILL message.
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