TabControl slows other controls and causes flickering

[pfleck]

Controls on a TabControl resize slowly and flicker, as also reported on varios stack overflow articles (see below). In cases where calculation intensive resizing is involved (e.g. charts), the GUI freezes shortly due to resizing and flickers.

Most articles suggest setting the WS_EX_COMPOSITED flag on the TabControl:

protected override CreateParams CreateParams {
  get {
    CreateParams cp = base.CreateParams;
    cp.ExStyle |= 0x02000000;  // Turn on WS_EX_COMPOSITED
    return cp;
  }
}

Some authors warn of possible side effects of this flag, so this should be properly tested.

​http://stackoverflow.com/questions/4690426/why-do-my-winforms-controls-flicker-and-resize-slowly ​http://stackoverflow.com/questions/3111841/tabcontrol-blinks-if-image-is-background ​http://stackoverflow.com/questions/2612487/how-to-fix-the-flickering-in-user-controls?lq=1 ​http://stackoverflow.com/questions/16925369/tabcontrol-flickering

[gkronber]

I quickly tested the patch to check whether this has an effect on the extreme lag of enabling / disabling of controls but found no noticeable improvement. It might still have a positive effect on resizing though. I have not tested this.