How to validate key combinations(AltGr+Key)?

Question

I need to set edit mode for an textbox when press (Alt+Key).I'm using German Keyboard. I have achieved this in US keyboard but not in German keyboard.i have tried this following code in KeyDown event.

if (e.Modifiers == (Keys.Control | Keys.Alt) 
   && e.KeyData != (Keys.RButton | Keys.LButton | Keys.ShiftKey | Keys.Alt | Keys.Control))
{
  //my code
}

The condition

e.KeyData != (Keys.RButton | Keys.LButton | Keys.ShiftKey | Keys.Alt | Keys.Control) 

will always true when click Alt key alone. but in US keyboard this condition will works fine.

Anyone suggest me how to achieve this.

Answer 1

found the reason.

split this condition e.KeyData != (Keys.RButton | Keys.LButton | Keys.ShiftKey | Keys.Alt | Keys.Control) to

e.KeyData != (Keys.RButton | Keys.ShiftKey | Keys.Control | Keys.Alt)
       && e.KeyData != (Keys.LButton | Keys.ShiftKey | Keys.Control | Keys.Alt)