让时间动起来 非原创

 public MainPage()
        {
            InitializeComponent();

            DispatcherTimer tmr = new DispatcherTimer();
            tmr.Interval = TimeSpan.FromSeconds(1);
            tmr.Tick += OnTimerTick;
            tmr.Start();
        }

        void OnTimerTick(object sender, EventArgs args)
        {
            txtblk.Text = DateTime.Now.ToString();
        }