Delphi TSplitter does not immediately refresh other controls when you are dragging it. To make a Delphi TSplitter immediately repaint the screen when you drag it with the mouse, set ResizeStyle := rsUpdate   About Me Oracle & Delphi software developer based in Perth, Western Australia Australian Delphi User Group – WA branch manager, past … <a href="https://scotthollows.com/2020/04/13/delphi-tsplitter-immediate-repaint-screen-while-dragging/" class="more-link">Continue reading