Hi Kyley
Yes, I do receive
WM_USER messages. This is how the DLL communicates. As I mentioned,
it works perfectly if I put all the message checking in the mainform,
but it doesn't work in the separate unit, even with the AllocateHWnd.
Here is all my
relevant code.
TMyComponent
= class(TComponent)
private
FHandle: HWnd;
procedure WndProc(var Message: TMessage);
end;
constructor
TMyComponent.Create;
begin
inherited Create(AOwner);
FHandle := AllocateHWnd(WndProc);
end;
destructor
TMyComponent.Destroy;
begin
DeallocateHWnd(FHandle);
inherited Destroy;
end;
procedure
TMyComponent.WndProc(var Message: TMessage);
begin
with Message do
if Msg = WM_USER then
begin
Result := lparam + wparam //(for example)
end
else Result := DefWindowProc(FHandle, Msg, wParam, lParam);
end;
I get a
couple messages when the program loads but I never get Msg = WM_USER.
Do you see any
problems with this code?
The following code,
however, when placed in the mainform does detect WM_USER messages.
TForm1
= class(TForm)
...
procedure WMUSER(var Message: TMessage); message WM_USER;
end;
procedure
TForm1.WMUSER(var Message: TMessage);
begin
with Message do
if Msg = WM_USER then showmessage('It Works!');
end;
I've tried different
combinations of the syntax, including the message
WM_USER; bit in the unit but it doesn't
make any difference at all. In fact I still get other messages when
the program starts.
Thanks for the help.
Ross.
-----
Original Message -----
Sent:
Monday, June 27, 2005 10:01 PM
Subject:
[Spam] Re: [DUG] Intercepting messages in separate units
Try the wrapper class just incase you have made a blooper. but it is
unlikely that you will ever receive a message with the ID WM_USER. that
is simply an offset to coordinate with windows messages. eg
WM_USERLOGON = WM_USER+1 is an example of a user defined message.
then
myobject = class(TObject)
procedure WMUSERLOGON(var msg:TMessage);message WM_USERLOGON;
end;
the above procedure will only ever receive that one message. You need
to know exactly what messages you are expecting from the dll.
if you use my wrapper, and attached an instance of the above object to
message handler it will route the messages to that instance..
Ross Levis wrote:
Thanks for that
Kyley. I managed to implement AllocateHWnd etc, and everything appears
correct and logical. It's picking up some Windows messages but not the
WM_USER messages being sent. WM_USER is message number 1024. I'm
getting Message.Msg = 28 and that's about it.
I tried the same
code in the mainform as a test and this worked but only after I
specified the following:
procedure
MyMessage(var Message: TMessage); message WM_USER;
If I leave off
"message WM_USER", then nothing gets through to the procedure in the
mainform at all.
I tried this in
the unit and it doesn't make any difference. Message 28 is still
getting to the procedure and no 1024.
You can tell I'm
no expert when it comes to this. Do I need to use your fancy looking
wrapper class?
I must be
missing something.
Thanks,
Ross.
-----
Original Message -----
Sent:
Monday, June 27, 2005 7:13 PM
Subject:
[Spam] Re: [DUG] Intercepting messages in separate units
in the forms unit
function AllocateHWnd(Method: TWndMethod): HWND; deprecated; { moved
to Classes.pas }
{$EXTERNALSYM AllocateHWnd}
procedure DeallocateHWnd(Wnd: HWND); deprecated; { moved
to Classes.pas }
read the help will sort you out just fine
Ross Levis wrote:
I'm writing
a component which communicates with a 3rd party DLL using WM_USER
messages. After loading the DLL, I need to tell the DLL the handle to
send user messages back to, so my unit can intercept them, but I don't
know where to get a handle from. I know how to do it in the mainform
of a program but not in a separate unit. The messages sent to the
mainform do not appear to reach my unit.
What do I
need to do to make this happen?
Thanks,
Ross.
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_______________________________________________
Delphi mailing list
[email protected]
http://ns3.123.co.nz/mailman/listinfo/delphi
_______________________________________________
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[email protected]
http://ns3.123.co.nz/mailman/listinfo/delphi
