[solved] Error: Type identifier expected on Ahwnd: HWND
lazarus / 21-General

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the_magik_mushroom · 2021-02-20 04:25

hello everyone,
I'm using a simple code to Hook the F10 key, it works well :

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses 
Windows var  PrevWndProc: WNDPROC;const  MY_ID=1; function
WndCallback(Ahwnd: HWND; uMsg: UINT; wParam: WParam; lParam:
LParam):LRESULT; stdcall;begin  if (uMsg=WM_HOTKEY) and (WParam=MY_ID)
then    begin      Application.Restore;    end; 
result:=CallWindowProc(PrevWndProc,Ahwnd, uMsg, WParam,
LParam);end; procedure TForm1.FormCreate(Sender: TObject);begin  PrevW
ndProc:=Windows.WNDPROC(SetWindowLong(Self.Handle,GWL_WNDPROC,PtrInt(@
WndCallback)));  RegisterHotKey(Self.Handle,MY_ID,0,vk_F10); // HOTKEY
F10end; procedure TForm1.FormDestroy(Sender: TObject);begin 
 UnRegisterHotkey(Self.Handle,MY_ID);end; 
The code compile without any issues, but when I copy/paste the exact
same code in another project, I get this error :

Error: Type identifier expected : on the Ahwnd: HWND;
Error: Incompatible type for arg no. 2: Got "<erroneous type>",
expected "LongWord" : on the result:=CallWindowProc(PrevWndProc,Ahwnd

I'm trying to understand how to avoid these errors, and specially why
the code is compiling in an empty exe and not in another project.
thank you

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Handoko · 2021-02-20 05:36

Hello the_magik_mushroom,
Welcome to the forum.

I copied/pasted your code to a new project. It works. I meant I didn't
get any compile-time error, as I am not a Windows user so I can't test
it. Here is the whole main source code:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
Unit1; {$mode objfpc}{$H+} interface uses  Classes, SysUtils, Forms,
Controls, Graphics, Dialogs, StdCtrls, Windows; type   { TForm1 }  
TForm1 = class(TForm)    procedure FormCreate(Sender: TObject);   
procedure FormDestroy(Sender: TObject);  private   public   end; var 
Form1: TForm1; implementation {$R *.lfm} { TForm1 } var  PrevWndProc:
WNDPROC;const  MY_ID=1; function WndCallback(Ahwnd: HWND; uMsg: UINT;
wParam: WParam; lParam: LParam):LRESULT; stdcall;begin  if
(uMsg=WM_HOTKEY) and (WParam=MY_ID) then    begin     
Application.Restore;    end; 
result:=CallWindowProc(PrevWndProc,Ahwnd, uMsg, WParam,
LParam);end; procedure TForm1.FormCreate(Sender: TObject);begin  PrevW
ndProc:=Windows.WNDPROC(SetWindowLong(Self.Handle,GWL_WNDPROC,PtrInt(@
WndCallback)));  RegisterHotKey(Self.Handle,MY_ID,0,vk_F10); // HOTKEY
F10end; procedure TForm1.FormDestroy(Sender: TObject);begin 
 UnRegisterHotkey(Self.Handle,MY_ID);end; end.
For your information, learning by copy/pasting code is bad especially
for beginners.

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the_magik_mushroom · 2021-02-20 17:32

thanks jamie! problem solved, I had a hWnd:THandle; in another Unit