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Programming => Packages and Libraries => Ported from Delphi/Kylix => Topic started by: Anonymous on January 06, 2006, 01:43:56 pm

Title: Tray Icon Problem
Post by: Anonymous on January 06, 2006, 01:43:56 pm

Hi!

I have problem with a tray icon program on win32.
The icon is created, but i can't get any messages from the tray icon.
If i use a local hook, it's works only on the mainform. I have a global hook too, but if i call a function from the dll, i get an error message:
Access Violation
Address : $00000000
Function : ??

I declarated the dll's functions this way:
  pointer(InstallHook) := GetProcAddress(Handle, 'InstallHook');
  pointer(UnInstallHook) := GetProcAddress(Handle, 'UninstallHook');

My dll source:

library keyboardhook;

{$mode objfpc}{$H+}

uses
  Classes, SysUtils, Windows, Messages;



var
  HookHandle: Cardinal = 0;
  WindowHandle: Cardinal = 0;
  voltuzenet : boolean = False;

function KeyboardHookProc(nCode: Integer; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall;
begin
//it's possible to call CallNextHookEx conditional only.
  Result := CallNextHookEx(HookHandle, nCode, wParam, lParam);
  case nCode < 0 of
    TRUE: exit; //if code smaller 0 nothing has to be done

    FALSE:
      begin
   Voltuzenet := True; // it means there is an message
      end;
  end;
end;

function InstallHook(Hwnd: Cardinal): Boolean; stdcall;
begin
  Result := False;
  if HookHandle = 0 then begin
   //First install the hook
    HookHandle := SetWindowsHookEx(WH_KEYBOARD, @KeyboardHookProc,
    HInstance, 0);
   //Save the given window handle
    WindowHandle := Hwnd;
    Result := TRUE;
  end;
  voltuzenet := False;
end;

function UninstallHook: Boolean; stdcall;
begin
//Uninstall hook from hook chain
  Result := UnhookWindowsHookEx(HookHandle);
  HookHandle := 0;
end;

function Volteuzenet : Boolean; stdcall;
begin
  Result := voltuzenet;
end;

exports
//Export the installation and deinstallation routine
  InstallHook,
  UninstallHook,
  Volteuzenet;  // it means, there is an message
begin
end.

First i load the dll at the dynamic way:
procedure TForm1.Button8Click(Sender: TObject);
begin
  lib := LoadLibrary('keyboardhook.dll');
  if lib <> INVALID_HANDLE_VALUE then begin
    //InstallHook := GetProcAddress(lib, 'InstallHook');
    //UnInstallHook := GetProcAddress(lib, 'UninstallHook');
  pointer(InstallHook) := GetProcAddress(Handle, 'InstallHook');
  pointer(UnInstallHook) := GetProcAddress(Handle, 'UninstallHook');
  pointer(Volteuzenet) := GetProcAddress(Handle, 'Volteuzenet');
  end
  else
    begin
      Showmessage ('Nem lehetett a dll-t betölteni!'); // it means : unlabe to load the dll
      FreeLIbrary(lib);
    end;
end;                        

After thet, i try to install the hook:
procedure TForm1.Button4Click(Sender: TObject);
begin
  InstallHook(Form1.Handle);
end;  

At this moment i get the error message :(

I have Lazarus 0.9.10beta, fpc 2.0.1.
I comlipped the dll, wiht the fpc 2.0.2 because the dll bug.

The Tray Program is compilled with the old fpc (fpc 2.0.1) because i try to compile the lazarus with the new fpc, and i get an error message.


What is wrong?
Is there any simlpe way to get a tray icon? Like a Component?

Thx.
Mammuth

ps: excuse me for my terrible english, i'm working on it

Title: Re: Tray Icon Problem
Post by: felipemdc on January 27, 2006, 03:23:14 pm

Quote

I have problem with a
What is wrong?
Is there any simlpe way to get a tray icon? Like a Component?

You may want to try TTrayIcon component. It features tray icons in an easy to use way, and is also multiplatform.

wiki.lazarus.freepascal.org/index.php/TrayIcon

It works currently on win32 and gtk. In the future it will also work with Gtk2, Carbon, Windows CE and Qt.