[angvelem]

Начнём:

Код:

var
  dc, memdc : HDC;
  bmp, oldbmp : HBITMAP;
...
function MessageMainProcess(Wnd : HWND; Msg : UINT; wParam, lParam : Integer) : Integer; stdcall;
var
  ps : PAINTSTRUCT;
begin
  case Msg of
    WM_CREATE :
    begin
      dc := GetDC(0);
      memdc := CreateCompatibleDC(dc);
      bmp := LoadGIFRes(hInstance, 'button_next', 'GIF');//Загрузка *.RES
      oldbmp := SelectObject(memdc, bmp);
    end;

    WM_PAINT :
    begin
      BeginPaint(Wnd, ps);
      BitBlt(ps.hdc, 0, 0, 100, 100, memdc, 0, 0, SRCCOPY);
      EndPaint(Wnd, ps);
    end;

    WM_DESTROY :
    begin
      DeleteObject(SelectObject(memdc, oldbmp));
      DeleteDC(memdc);
      ReleaseDC(0, dc);
      PostQuitMessage(0);
      Exit;
    end;
  end;
  Result := DefWindowProc(Wnd, Msg, wParam, lParam);
end;