Code:
procedure TForm1.CacheTexture(const ATexture: TCustomLockableTexture);
var
  LPixels: TLockedPixels;
begin
  if not ATexture.Lock(LPixels) then 
  begin
    ShowMessage('lock failed');
    Exit;
  end else
    ShowMessage('lock success');
  //
  try
     if not LPixels.valid then
        ShowMessage('invalid pixels');
  finally
     ATexture.Unlock;
  end;
end;
----------print----------
--lock success