XAML代码：

1 
      
       5     
       
        6         
        7     
       8 
      

.CS代码：

1 using System; 2 using System.Windows; 3 using System.Windows.Controls; 4 using System.Windows.Media.Animation; 5  6 namespace 关键帧动画 7 { 8     /// 
 9     /// MainWindow.xaml 的交互逻辑10     /// 
11     public partial class MainWindow : Window12     {13         public MainWindow()14         {15             InitializeComponent();16         }17 18         private void Window_Loaded(object sender, System.Windows.RoutedEventArgs e)19         {20             // 在此处添加事件处理程序实现。21             DoubleAnimationUsingKeyFrames dak=new DoubleAnimationUsingKeyFrames();22             dak.KeyFrames.Add(new LinearDoubleKeyFrame(0,KeyTime.FromTimeSpan(TimeSpan.FromSeconds(0))));23             dak.KeyFrames.Add(new LinearDoubleKeyFrame(240,KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3))));24             dak.KeyFrames.Add(new LinearDoubleKeyFrame(240,KeyTime.FromTimeSpan(TimeSpan.FromSeconds(6))));25             dak.KeyFrames.Add(new LinearDoubleKeyFrame(0,KeyTime.FromTimeSpan(TimeSpan.FromSeconds(9))));26             dak.BeginTime=TimeSpan.FromSeconds(2);27             dak.RepeatBehavior=new RepeatBehavior(2);28             this.border1.BeginAnimation(Border.WidthProperty,dak);29         }30     }31 }