Handle einer Form aus Taskbareintrag erhalten

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Anbei schonmal ein Entwurf meiner Delphi Uebersetzung des 2. Codefragmentes.
Es liefert von einem gegebenem Buttonindex das Handle des zugehoerigen Fensters.

Delphi-Quellcode:

function GetHandleFromButtonIndex(ButtonIndex: Word): HWND;
const
  BUFFER_SIZE = $1000;
var
  hwndTaskbar: HWND;
  // variables that needed to open taskbar (explorer) process
  taskbarProcessID: DWORD;
  taskbarProcessHandle: THandle;
 // variable that helds pointer to a remote buffer in taskbar process
  taskbarProcessBuffer: Pointer;
  i: Integer;
  dwBytesRead: DWORD;
  lpRemoteData: Pointer;
  tbButton: TTBBUTTON;
  PtbButton: Pointer;
  localBuffer: array[0..BUFFER_SIZE - 1] of Byte;
  pLocalBuffer: ^Byte;
  ipLocalBuffer: Pointer;
  btnWindowHandle: HWND;
begin
  Result := 0;
  // find Windows Taskbar
  hwndTaskbar := getTaskbarHWND;
  if hwndTaskbar <> 0 then
  begin
    // obtain taskbar process id - by window
    GetWindowThreadProcessId(hwndTaskbar, @taskbarProcessID);
    // open taskbar process
    taskbarProcessHandle := OpenProcess(PROCESS_ALL_ACCESS, False, taskbarProcessID);
    if taskbarProcessHandle <> 0 then
    try
      // allocate space for remote buffer in taskbar process
      taskbarProcessBuffer := VirtualAllocEx(taskbarProcessHandle, nil, BUFFER_SIZE, MEM_COMMIT, PAGE_READWRITE);
      if Assigned(taskbarProcessBuffer) then
      begin
        // declare and prepare variables that will held data
        // about PRESSED button in a taskbar
        PtbButton := @tbButton;
        // Now, retrieve information about the PRESSED button in a taskbar / data is placed in remote buffer
        SendMessage(hwndTaskbar, TB_GETBUTTON, ButtonIndex, Integer(taskbarProcessBuffer));
        // And now, the remote data about PRESSED button is transferred to a local variable
        dwBytesRead := 0;
        ReadProcessMemory(taskbarProcessHandle, taskbarProcessBuffer, PtbButton, SizeOf(TBBUTTON), dwBytesRead);
        // the window handle is in dwData field of TBBUTTON structure (the first 4 bytes)
        pLocalBuffer := @localBuffer[0];
        ipLocalBuffer := pLocalBuffer;
        // initialize remote buffer
        lpRemoteData := @tbButton.dwData;
        // and read the dwData fields of a TBBUTTON from remote process
        dwBytesRead := 0;
        ReadProcessMemory(taskbarProcessHandle, lpRemoteData, ipLocalBuffer, SizeOf(Pointer), dwBytesRead);
        // obtain window handle, copy first 4 bytes
        Move(ipLocalBuffer, btnWindowHandle, 4);
        Result := btnWindowHandle;
        if Assigned(taskbarProcessBuffer) then
          VirtualFreeEx(taskbarProcessHandle, taskbarProcessBuffer, 0, MEM_RELEASE);
      end;
    finally
      CloseHandle(taskbarProcessHandle);
    end;
  end;
end;