C#

public delegate void TimerEventHandler(object sender, TimerEventArgs e);
 
public class TimerEventArgs : EventArgs
{
  //TODO: put in property procedures here for each event argument
}
 
 
//---in the class that raises an event---
public event TimerEventHandler TimerRing;
protected OnTimerRing(TimerEventArgs e)
{
  if(TimerRing!=null) TimerRing(this,e);
}
 
 
//---in the class that consumes the event---
private void TimerRung(object sender, TimerEventArgs e)
{
  //handle the event here
}
 
 
//---in the method that hooks up the event---
AlarmClock.TimerRing+=new TimerEventHandler(this.TimerRung);

Button btn = (Button) sender;			
if(switchMC)			
{	
   btn.Text="1";				
   switchMC=false;			
}			
else 
{		
   btn.Text="0";				
   switchMC=true;			
}

Button btn = (Button) sender;
btn.Text = switchMC ? "1" : "0";
switchMC=!switchMC;

Button btn = (Button) sender;
btn.Text = btn.Text=="0" ? "1" : "0";

protected override bool IsInputKey(Keys key)
{
   if (key.KeyCode == Keys.Up) return true;
   else if (key.KeyCode == Keys.Down) return true;
   else if (key.KeyCode == Keys.Left) return true;
   else if (key.KeyCode == Keys.Right) return true;
   else return base.IsInputKey(key);
}