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