先准备一个基本的xaml页面
结构不复杂，里面就放了一张图片，同时预置了一个动画storyTest，里面把几种常见的动画形式都列在里面了，下面就来看看如何动态改变storyTest动画的属性(比如改变旋转的起始角度之类)
1.直接加x:Name，然后引用赋值
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<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="img" Storyboard.TargetProperty="(UIElement.Projection).(PlaneProjection.RotationY)">
2 <EasingDoubleKeyFrame KeyTime="00:00:01" Value="360" x:Name="yFrom"/>
3 <EasingDoubleKeyFrame KeyTime="00:00:02" Value="720" x:Name="yTo"/>
4</DoubleAnimationUsingKeyFrames>
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注意高亮部分，然后象这样引用
System.Windows.Media.Animation.EasingDoubleKeyFrame yFrom = this.FindName("yFrom") as System.Windows.Media.Animation.EasingDoubleKeyFrame;
yFrom.Value = 20;
yFrom.Value = 20;
这样我们就把00:00:01秒时角度由360改为20度了
2.利用StoryBoard的Children属性
DoubleAnimationUsingKeyFrames _rotate = storyTest.Children[0] as DoubleAnimationUsingKeyFrames;
_rotate.KeyFrames[0].Value = 90;//修改旋转角度的值
_rotate.KeyFrames[1].Value = 180;
storyTest.RepeatBehavior = RepeatBehavior.Forever;//指定为一直播放
//this.storyTest.RepeatBehavior = new RepeatBehavior(2);//播放2次
_rotate.KeyFrames[0].Value = 90;//修改旋转角度的值
_rotate.KeyFrames[1].Value = 180;
storyTest.RepeatBehavior = RepeatBehavior.Forever;//指定为一直播放
//this.storyTest.RepeatBehavior = new RepeatBehavior(2);//播放2次
这样我们就把旋转的角度值从360,720改为90,180了
说明：StoryBoard的Children属性得到的是一个Timeline的集合，而DoubleAnimationUsingKeyFrames等这些基本的关键帧类型都是继承自Timeline，因此可以用as安全的把Timeline向下转化为DoubleAnimationUsingKeyFrames
3.动态添加/删除关键帧
当xaml中预定义的关键帧不满足要求时，这种方法就几乎成了唯一选择
storyTest.Children.Clear();//清除原来的动画设定，仅保留一个空壳
DoubleAnimationUsingKeyFrames _new_rotate = new DoubleAnimationUsingKeyFrames();
EasingDoubleKeyFrame _frame1 = new EasingDoubleKeyFrame();
_frame1.Value = 180;
_frame1.KeyTime = new TimeSpan(0, 0, 0, 1);
EasingDoubleKeyFrame _frame2 = new EasingDoubleKeyFrame();
_frame2.Value = 0;
_frame2.KeyTime = new TimeSpan(0, 0, 0, 2);
EasingDoubleKeyFrame _frame3 = new EasingDoubleKeyFrame();
_frame3.Value = 90;
_frame3.KeyTime = new TimeSpan(0, 0, 0, 5);
_new_rotate.KeyFrames.Add(_frame1);
_new_rotate.KeyFrames.Add(_frame2);
_new_rotate.KeyFrames.Add(_frame3);
storyTest.Children.Add(_new_rotate);
Storyboard.SetTarget(_new_rotate, this.img);
Storyboard.SetTargetProperty(_new_rotate, new PropertyPath("(UIElement.Projection).(PlaneProjection.RotationY)"));
storyTest.AutoReverse = false;
//storyTest.FillBehavior = FillBehavior.Stop;//加入这一行后，不管AutoReverse设置为何值，都会回复原状
storyTest.Begin();
DoubleAnimationUsingKeyFrames _new_rotate = new DoubleAnimationUsingKeyFrames();
EasingDoubleKeyFrame _frame1 = new EasingDoubleKeyFrame();
_frame1.Value = 180;
_frame1.KeyTime = new TimeSpan(0, 0, 0, 1);
EasingDoubleKeyFrame _frame2 = new EasingDoubleKeyFrame();
_frame2.Value = 0;
_frame2.KeyTime = new TimeSpan(0, 0, 0, 2);
EasingDoubleKeyFrame _frame3 = new EasingDoubleKeyFrame();
_frame3.Value = 90;
_frame3.KeyTime = new TimeSpan(0, 0, 0, 5);
_new_rotate.KeyFrames.Add(_frame1);
_new_rotate.KeyFrames.Add(_frame2);
_new_rotate.KeyFrames.Add(_frame3);
storyTest.Children.Add(_new_rotate);
Storyboard.SetTarget(_new_rotate, this.img);
Storyboard.SetTargetProperty(_new_rotate, new PropertyPath("(UIElement.Projection).(PlaneProjection.RotationY)"));
storyTest.AutoReverse = false;
//storyTest.FillBehavior = FillBehavior.Stop;//加入这一行后，不管AutoReverse设置为何值，都会回复原状
storyTest.Begin();
在这里我们把原来storyTest中的动画设定全部清空 了，同时增加了一个三帧的动画
欢迎转载，但请注明来自菩提树下的杨过(http://yjmyzz.cnblogs.com/)