Lazarus

Programming => Operating Systems => Windows => Topic started by: Dibo on June 11, 2011, 11:09:47 pm

Title: [SOLVED] Process Messages in console application
Post by: Dibo on June 11, 2011, 11:09:47 pm

Hi,

I have console application for windows which waiting for message sent from other application with SendMessage (so it's blocking until my application response). I have simple loop which waiting for this message. Console application create dummy non visible window (CreateWindowEx()) which handle this message:

Code: Pascal  [Select][+][-]

1. program Test;
2.  
3. uses Windows;
4.  
5. var
6.   ServiceWnd: HWND;
7.   ServiceWndClass: Windows.TWndClass;
8.  
9.   { Queue message handling }
10.   function ServiceWndProc(HWindow: HWnd; Message: UINT; WParam: WPARAM; LParam: LPARAM): Longint;stdcall;
11.   begin
12.     Result:=0;
13.     { Client response }
14.     if (Message=MyMessage) then
15.     begin
16.       Writeln('Got Message');
17.       Result := 1;
18.     end else
19.     { Default }
20.     Result:=DefWindowProc(HWindow,Message,WParam,LParam);
21.   end;
22.  
23. begin
24.   ServiceWndClass.lpfnWndProc    := @ServiceWndProc;
25.   ServiceWndClass.hInstance        := HInstance;
26.   ServiceWndClass.lpszClassName := 'DemoClass';
27.   ServiceWnd := CreateWindowEx(WS_EX_TOOLWINDOW, PChar('DemoClass'),
28.     'Demo', WS_POPUP {!0}, 0, 0, 0, 0, 0, 0, HInstance, nil);
29.   if (ServiceWnd=0) then
30.     Exit;
31.  
32.   while True do
33.     Sleep(10);
34.  
35.   DestroyWindow(ServiceWnd);
36. end;
37.  

With this code, application which send message to me freezing until I terminate my console application. It seems that my console don't send response correctly to SendMessage caller. If I add Application.ProcesMessages to my loop then it works fine but I must add LCL and interfaces to my simply console application. What ProcessMessages do that caller get response?

Regards

Title: Re: Process Messages in console application
Post by: typo on June 11, 2011, 11:29:46 pm

Place the caret over Application.ProcessMessages on code editor. Then use Alt + Up to find the declaration and Ctrl + Shift + Down to find the procedure of function.

(If I understand your question)

Title: Re: [SOLVED] Process Messages in console application
Post by: Dibo on June 11, 2011, 11:41:22 pm

I tried that but stopped on WidgetSet.AppProcessMessages which is abtract (I should search it in lazarus source). But I found solution. I must peek messages in loop by my self:

Code: Pascal  [Select][+][-]

1.   while true do begin
2.     if PeekMessage(Msg,0,0,0,0) then
3.     begin
4.       GetMessage(Msg,0,0,0);
5.       TranslateMessage(Msg);
6.       DispatchMessage(Msg);
7.     end;
8.     Sleep(10);
9.   end;
10.  

Sorry for false alarm, I am not familiar in console applications.

Regards