WPF中Timer与DispatcherTimer类

采用System.Timer，使用Invoke或者BeginInvoke的方式进行UI的更新的方式（好处在于：在DispatcherTimer里面执行等待动作或者时间过长，可能会导致UI假死）
“`
using System;
using System.Windows;
using System.Timers;
using System.Windows.Threading;

namespace TimerTest
{
///
/// Interaction logic for MainWindow.xaml
///
public partial class MainWindow : Window
{
private Timer aTimer = null;

    private delegate void TimerDispatcherDelegate();

    public MainWindow()
    {
        InitializeComponent();

        aTimer = new Timer(1000);
        aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
        aTimer.Interval = 1000;
        aTimer.Enabled = true;
    }

    private void OnTimedEvent(object sender, EventArgs e)
    {
        this.Dispatcher.Invoke(DispatcherPriority.Normal,
            new TimerDispatcherDelegate(updateUI));
    }

    private void updateUI()
    {
        timeLabel.Content = DateTime.Now.ToUniversalTime();
    }
}

}