Question

I have a form with 50 or more controls which I create and add at runtime. I don’t want to see then appear one by one; I would rather disable drawing/start buffering at the start & then see them all appear at once.

I seem to recall doing something like this in BCB about 10 years ago, but forget how.

Answer 1

I’m not sure if there’s a Delphi-specific method to do this, but using the Win32 API, this is done through the WM_SETREDRAW message.

Edit: Thanks to Ken White and Sertac Akyuz for the sample code below.

begin
  // Defer updates
  SendMessage(Handle, WM_SETREDRAW, WPARAM(False), 0);
  try
    // Create all your controls here
  finally
    // Make sure updates are re-enabled
    SendMessage(Handle, WM_SETREDRAW, WPARAM(True), 0);
    // Invalidate;  // Might be required to reflect the changes  
  end;
end;