Flicking TElEdit-Controls

Quanos Service Solutions GmbH

The TElEdit-Controls are flickering very strong even in simple resizable forms.

See attached Test-project.

Eugene Balabuev (LMD)

Thanks for report, I'll look...

Eugene Balabuev (LMD)

Hi,

Flickering happens due to extensive panels redrawings, because of enabled transparency. I suggest you to turn off TransparentXPThemes property in each of TElPanel.

Quanos Service Solutions GmbH

This helps to reduce flickering, but doesn't make it disappear.
Even when setting DoubleBuffer = True, it flickers.

And it flickers very strong in complex GUIs.

I try to active VCL-Theming and Flickering disapear.
But it crashes my real application on startup with activate of VCL-Theming :-(

Quanos Service Solutions GmbH

We could reduce flickering (in our application) by adding following code

procedure WMNCPaint(var Msg: TMessage); message WM_NCPAINT;

procedure TCustomElEdit.WMNCPaint(var Msg: TMessage);
var
  WS: DWORD;
begin
  WS  := GetWindowLong(Handle, GWL_STYLE);
  if WS and WS_BORDER <> 0 then
  begin
    FPreventStyleChange := True;
    SetWindowLong(Handle, GWL_STYLE, WS and
not WS_BORDER);
  end
end;

Eugene Balabuev (LMD)

Hi,

Effectively what your code do, is prevents "inherited" from been called. So, this can be simplified to:

procedure TCustomElEdit.WMNCPaint(var Msg: TMessage);
begin

  // Do not call inherited.
end;

And it works, you right.