DispatcherTimer mytask = new DispatcherTimer();
        public test()
        {
            InitializeComponent();

            mytask = new System.Windows.Threading.DispatcherTimer();
            mytask.Tick += new EventHandler(myEvent);
            mytask.Interval = , , );
            mytask.Start();

        }
        void myEvent(object sender, EventArgs e)
        {            //你需要执行的函数，比如。：
            NavigationService.Navigate(new Uri("/index.xaml", UriKind.Relative));
        }