Application.HookMainWindow(AppWindowHook)

[bobonwhidbey]

This question was asked 3 years ago on this forum, without an answer. Perhaps there is one today. I'm converting from Delphi to Lazarus. In one unit, on a mouse up event, I have:

Code: Pascal  [Select][+][-]

1. const
2.   WM_Selected = WM_App + 100;
3. begin
4.      SendMessage(Application.Handle, WM_Selected, 0, 0);
5.  

in another unit I have:

Code: Pascal  [Select][+][-]

1. function TMyApp.AppWindowHook(var Message: TMessage): Boolean;
2. begin
3.   if  message.msg = WM_Selected then
4.     DoSomething;
5. end;
6.  
7. procedure TMyApp.FormShow(Sender: TObject);
8. begin
9.   Application.HookMainWindow(AppWindowHook);
10. end;
11.  
12. procedure TMyApp.FormDestroy(Sender: TObject);
13. begin
14.   Application.UnhookMainWindow(AppWindowHook);
15. end;
16.  

Lazaraus can not compile MyApp  - Error: identifier idents no member "HookMainWindow", etc.

How can I do this is Lazarus. Is there another unit I need in Uses?

[balazsszekely]

For custom messages you don't need hooks. Just add windows to the uses clauses.(I know you' re under windows ). For a cross platform solution, replace WM_ with the appropriate message from unit LMessages.pp.

Code: Pascal  [Select][+][-]

1. const
2.   WM_Selected = WM_APP + 100;
3.  
4. type
5.   { TForm1 }
6.  
7.   TForm1 = class(TForm)
8.     Button1: TButton;
9.     procedure Button1Click(Sender: TObject);
10.   private
11.     { private declarations }
12.     procedure OnMyMessage(var Msg: TMessage); message WM_Selected;
13.   public
14.     { public declarations }
15.   end;
16.  
17. var
18.   Form1: TForm1;
19.  
20. implementation
21.  
22. {$R *.lfm}
23.  
24. { TForm1 }
25.  
26. procedure TForm1.Button1Click(Sender: TObject);
27. begin
28.   SendMessage(Form1.Handle, WM_Selected, Integer(555), 0);
29. end;
30.  
31. procedure TForm1.OnMyMessage(var Msg: TMessage);
32. begin
33.   ShowMessage(IntToStr(Msg.wParam));
34. end;                              
35.  

[bobonwhidbey]

Thanks for your perfect solution GetMem. It helps when you don't make typos like I did initially