using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace WpfClock
{
 using System.Threading;
 using System.Windows.Threading;
 /// <summary>
 /// MainWindow.xaml 的交互逻辑
 /// </summary>
 public partial class MainWindow : Window
 {
  //计时器
  System.Timers.Timer timer = new System.Timers.Timer(1000);
  public MainWindow()
  {
   InitializeComponent();
   #region 初始化时间
   secondPointer.Angle = DateTime.Now.Second * 6;
   minutePointer.Angle = DateTime.Now.Minute * 6;
   hourPointer.Angle = (DateTime.Now.Hour * 30) + (DateTime.Now.Minute * 0.5);
   this.labTime.Content = DateTime.Now.ToString("HH:mm:ss");
   #endregion
   timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
   timer.Enabled = true;
  }

  private void Grid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
  {
   //进行拖放移动
   this.DragMove();
  }
  private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
  {
   //UI异步更新
   this.Dispatcher.Invoke(DispatcherPriority.Normal, (Action)(() =>
   {
    //秒针转动,秒针绕一圈360度，共60秒，所以1秒转动6度
    secondPointer.Angle = DateTime.Now.Second * 6;
    //分针转动,分针绕一圈360度，共60分，所以1分转动6度
    minutePointer.Angle = DateTime.Now.Minute * 6;
    //时针转动,时针绕一圈360度，共12时，所以1时转动30度。
    //另外同一个小时内，随着分钟数的变化(绕一圈60分钟），时针也在缓慢变化（转动30度，30/60=0.5)
    hourPointer.Angle = (DateTime.Now.Hour * 30)+ (DateTime.Now.Minute * 0.5);
    //更新时间值
    this.labTime.Content = DateTime.Now.ToString("HH:mm:ss");
   }));
  }

 }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace WpfClock
{
 using System.Threading;
 using System.Windows.Threading;
 /// <summary>
 /// MainWindow.xaml 的交互逻辑
 /// </summary>
 public partial class MainWindow : Window
 {
  //计时器
  System.Timers.Timer timer = new System.Timers.Timer(1000);
  public MainWindow()
  {
   InitializeComponent();
   #region 初始化时间
   secondPointer.Angle = DateTime.Now.Second * 6;
   minutePointer.Angle = DateTime.Now.Minute * 6;
   hourPointer.Angle = (DateTime.Now.Hour * 30) + (DateTime.Now.Minute * 0.5);
   this.labTime.Content = DateTime.Now.ToString("HH:mm:ss");
   #endregion
   timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
   timer.Enabled = true;
  }

  private void Grid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
  {
   //进行拖放移动
   this.DragMove();
  }
  private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
  {
   //UI异步更新
   this.Dispatcher.Invoke(DispatcherPriority.Normal, (Action)(() =>
   {
    //秒针转动,秒针绕一圈360度，共60秒，所以1秒转动6度
    secondPointer.Angle = DateTime.Now.Second * 6;
    //分针转动,分针绕一圈360度，共60分，所以1分转动6度
    minutePointer.Angle = DateTime.Now.Minute * 6;
    //时针转动,时针绕一圈360度，共12时，所以1时转动30度。
    //另外同一个小时内，随着分钟数的变化(绕一圈60分钟），时针也在缓慢变化（转动30度，30/60=0.5)
    hourPointer.Angle = (DateTime.Now.Hour * 30)+ (DateTime.Now.Minute * 0.5);
    //更新时间值
    this.labTime.Content = DateTime.Now.ToString("HH:mm:ss");
   }));
  }

 }
}

 <Rectangle.RenderTransform>
  <RotateTransform x:Name="hourPointer" CenterX="0" CenterY="70" Angle="90" />
 </Rectangle.RenderTransform>