Hotkeys avoiding leave event c# win. form

I'm surprised that using a mnemonic key-combination on a Button would fire when a TextBox in WinForms has focus, because it "captures" the mouse, however I'm not surprised it doesn't fire the 'Leave Event in the sense that ties in with dim memories of being frustrated using mnemonics.

So, a few years ago I gave up on using mnemonics on WinForm Controls on a Form, or in Container Controls (for Menus they seem to work fine).

I use this kind of code now:

// detect Alt-S
private Keys ShiftAltS = Keys.Shift | Keys.Alt | Keys.S;

// define in Form Scope
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if (keyData.HasFlag(ShiftAltS))
    {
        // test here to see if a particular Control
        // or Controls have the current Focus
        // and use a Switch/Case statement or whatever
        // to select which Control you want Focus to go to

        // here's a sample of what I would do to redirect Focus
        // from TextBox to Button:
        if(ActiveControl == YourTextBox)
        {
          YourButton.Focus();
          YourButton.Capture(); // optional: will have some side-effects
          return true;
        }
    }
    return base.ProcessCmdKey(ref msg, keyData);
}

Actually, I use a fancier version of this that I intend to write an article or tip/trick about this year, here. But, this code, I hope, demonstrates a useful alternative if you don't get anywhere with mnemonics.