How do you disable a Timer?

TinyCLR OS
1

How do you disable a Timer ?
When you set it to null, it keeps firing. And at some strange interval !

        private Timer _Off_Timer;

        public LCD_Backlight()
        {
            _GPIO_LED = GpioController.GetDefault().OpenPin(Hardware.LCD_BackLight_Pin);
            _GPIO_LED.SetDriveMode(GpioPinDriveMode.Output);
            _GPIO_LED.Write(GpioPinValue.Low);
        }

        public void On()
        {
            _GPIO_LED.Write(GpioPinValue.High);
            _Off_Timer = new Timer(Timer_Elapsed, null, 
                       TimeSpan.FromSeconds(5),
                       TimeSpan.FromSeconds(5));
        }

        private void Timer_Elapsed(object state)
        {
            _GPIO_LED.Write(GpioPinValue.Low);
            _Off_Timer = null;
        }
2

how about:

_Off_Timer.Dispose();

3

Yeppers !!
That worked. Thanks!

4

Looks like this works too

_Off_Timer.Change(-1,-1);