在Windows 8 WinRT中访问振动功能？

using System;
using Windows.Phone.Devices.Notification;

public class VibrationHelper
{
    public static void Vibrate(int milliseconds)
    {
        VibrationDevice vibrationDevice = VibrationDevice.GetDefault();
        if (vibrationDevice != null)
        {
            vibrationDevice.Vibrate(TimeSpan.FromMilliseconds(milliseconds));
        }
    }

    public static void StopVibration()
    {
        VibrationDevice vibrationDevice = VibrationDevice.GetDefault();
        if (vibrationDevice != null)
        {
            vibrationDevice.Cancel();
        }
    }
}