c# 计时器 DispatcherTimer 和 System.Timers.Timer

DispatcherTimer 

此类执行方法跟UI处于同一个线程

private void StartTimer()
        {
            DispatcherTimer dispatcherTimer = new DispatcherTimer();
            dispatcherTimer.Tick += OnTimerHandler;
            dispatcherTimer.Interval = new TimeSpan(0, 0, 0,0,100);//每100毫秒刷新一次
            dispatcherTimer.Start();
        }

        private void OnTimerHandler(object sender,EventArgs e)
        {
            string strTime = DateTime.Now.Hour + ":" + DateTime.Now.Minute + ":" + DateTime.Now.Second + ":" + DateTime.Now.Millisecond;
            lbTime.Content = strTime;
        }

System.Timers.Timer

此类会另起一个线程，所以当操作UI控件的时候需要注意。

   public partial class TimerWindow : Window
    {
        System.Timers.Timer _timer = new System.Timers.Timer(1000);//设置时间间隔 毫秒

        public TimerWindow()
        {
            InitializeComponent();

            _timer.Elapsed += OnTimerHandler;
            _timer.AutoReset = true;//  false只触发一次  true重复触发
        }

        private void OnStart()
        {
            _timer.Start();
        }

        private void OnStop()
        {
            _timer.Stop();
        }

        private void OnTimerHandler(object sender, System.Timers.ElapsedEventArgs e)
        {
            //需要注意Time类和UI不在同一个线程问题
            string strTime = DateTime.Now.ToLongTimeString();
            Action cb = delegate () {
                lbTime.Content = strTime;
            };
            this.Dispatcher.Invoke(cb);
        }

        private void btnStart_Click(object sender, RoutedEventArgs e)
        {
            OnStart();
        }

        private void btnStop_Click(object sender, RoutedEventArgs e)
        {
            OnStop();
        }
    }