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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_______________________________________________
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http://ns3.123.co.nz/mailman/listinfo/delphi
_______________________________________________
Delphi mailing
list
[email protected]
http://ns3.123.co.nz/mailman/listinfo/delphi
_______________________________________________
Delphi mailing list
[email protected]
http://ns3.123.co.nz/mailman/listinfo/delphi
