Global keyboard hook does not get specific characters

Question

I recently found a sample code for global keyboard hooks and decided to study it. It is the same old code described here Windows Global Keyboard Hook - Delphi.

It works fine for basic latin characters but in some languages the user has to press a key and after that the desired letter key to get the special character. For example in Greek language the character ά is produced by pressing the ; key and then the α key. The hook will allow only the character α. I found out that pressing the keys in rapid succession works.

Is there a possible workaround to fix this minor issue? Thanks in advance.

The code I use:

library HkT;

uses
  Windows,
  Messages,
  SysUtils,
  Classes;

{$R *.RES}

type
  PHookRec = ^THookRec;
  THookRec = record
    //AppHnd: Integer;
    MemoHnd: Integer;
  end;

var
  Hooked: Boolean;
  hKeyHook, hMemo, hMemFile: HWND;//, hApp: HWND;
  PHookRec1: PHookRec;

function KeyHookFunc(Code, VirtualKey, KeyStroke: Integer): LRESULT; stdcall;
var
  KeyState1: TKeyBoardState;
  AryChar: array[0..1] of Char;
  Count: Integer;
begin
  Result := 0;
  if Code = HC_NOREMOVE then Exit;
  Result := CallNextHookEx(hKeyHook, Code, VirtualKey, KeyStroke);
  {I moved the CallNextHookEx up here but if you want to block
   or change any keys then move it back down}
  if Code < 0 then
    Exit;

  if Code = HC_ACTION then
  begin
    if ((KeyStroke and (1 shl 30)) <> 0) then
      if not IsWindow(hMemo) then
      begin
       {I moved the OpenFileMapping up here so it would not be opened
        unless the app the DLL is attatched to gets some Key messages}
        hMemFile  := OpenFileMapping(FILE_MAP_WRITE, False, 'Global7v9k');
        PHookRec1 := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);
        if PHookRec1 <> nil then
        begin
          hMemo := PHookRec1.MemoHnd;
          //hApp  := PHookRec1.AppHnd;
        end;
      end;
    if ((KeyStroke and (1 shl 30)) <> 0) then
    begin
      GetKeyboardState(KeyState1);
      Count := ToAscii(VirtualKey, KeyStroke, KeyState1, AryChar, 0);
      if Count = 1 then
      begin
        case VirtualKey of
          VK_DELETE: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('D'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('L'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
          VK_BACK: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('B'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('S'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
          VK_TAB: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('T'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('B'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
          VK_RETURN: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('E'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('N'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(AryChar[0]), 0);
          end;
          VK_LSHIFT, VK_RSHIFT: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('S'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('F'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
          VK_ESCAPE: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('E'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('S'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
          VK_LCONTROL, VK_RCONTROL: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('C'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('T'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
          VK_MENU: begin
            SendMessage(hMemo, WM_CHAR, Ord('['), 0);
            SendMessage(hMemo, WM_CHAR, Ord('A'), 0);
            SendMessage(hMemo, WM_CHAR, Ord('L'), 0);
            SendMessage(hMemo, WM_CHAR, Ord(']'), 0);
          end;
        else
          SendMessage(hMemo, WM_CHAR, Ord(AryChar[0]), 0);
          {I included 2 ways to get the Charaters, a Memo Hnadle and
           a WM_USER+1678 message to the program}
//          PostMessage(hApp, WM_USER + 1678, Ord(AryChar[0]), 0);
        end;
      end;
    end;
  end;
end;


function StartHook(MemoHandle, AppHandle: HWND): Byte; export;
begin
  Result := 0;
  if Hooked then
  begin
    Result := 1;
    Exit;
  end;
  if not IsWindow(MemoHandle) then
  begin
    Result := 4;
    Exit;
  end;
  hKeyHook := SetWindowsHookEx(WH_KEYBOARD, KeyHookFunc, hInstance, 0);
  if hKeyHook > 0 then
  begin
    {you need to use a mapped file because this DLL attatches to every app
     that gets windows messages when it's hooked, and you can't get info except
     through a Globally avaiable Mapped file}
    hMemFile := CreateFileMapping($FFFFFFFF, // $FFFFFFFF gets a page memory file
      nil,                // no security attributes
      PAGE_READWRITE,     // read/write access
      0,                  // size: high 32-bits
      SizeOf(THookRec),   // size: low 32-bits
      //SizeOf(Integer),
      'Global7v9k');    // name of map object
    PHookRec1 := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);
    hMemo := MemoHandle;
    PHookRec1.MemoHnd := MemoHandle;
    //hApp := AppHandle;
    //PHookRec1.AppHnd := AppHandle;
    {set the Memo and App handles to the mapped file}
    Hooked := True;
  end
  else
    Result := 2;
end;

function StopHook: Boolean; export;
begin
  if PHookRec1 <> nil then
  begin
    UnmapViewOfFile(PHookRec1);
    CloseHandle(hMemFile);
    PHookRec1 := nil;
  end;
  if Hooked then
    Result := UnhookWindowsHookEx(hKeyHook)
  else
    Result := True;
  Hooked := False;
end;

procedure EntryProc(dwReason: DWORD);
begin
  if (dwReason = Dll_Process_Detach) then
  begin
    if PHookRec1 <> nil then
    begin
      UnmapViewOfFile(PHookRec1);
      CloseHandle(hMemFile);
    end;
    UnhookWindowsHookEx(hKeyHook);
  end;
end;

exports
  StartHook,
  StopHook;

begin
  PHookRec1 := nil;
  Hooked := False;
  hKeyHook := 0;
  hMemo := 0;
  DLLProc := @EntryProc;
  EntryProc(Dll_Process_Attach);
end.