C# 如果ScatterViewItem更改其大小，则动画出现问题

是根据其大小设置我的ScatterViewItem的内容。因此，我编写了一段调用情节提要的代码，以便根据ScatterViewItem的大小设置内容：

 private void Package_ContactDown(object sender, ContactEventArgs e)
        {
            ScatterViewItem svi = new ScatterViewItem();
            svi.Orientation = 0;
            removeShadow(svi);
            svi.IsActive = true;
            PackageView view = new PackageView(sourceFile, this);
            view.setScatterViewItem(svi);
            svi.Width = 1024;
            svi.Height = 768;
            svi.Center = new Point(512, 384);
            Viewbox box = new Viewbox();
            box.Child = view;

            Viewbox boxSmall = new Viewbox();
            boxSmall.Name = "SmallLayout";
            TextBlock txt = new TextBlock();
            txt.Text = "Package of class";
            boxSmall.Child = txt;
            boxSmall.Visibility = System.Windows.Visibility.Collapsed;
            boxSmall.Opacity = 0;
            boxSmall.IsHitTestVisible = false;

            Grid g = new Grid();
            g.Children.Add(box);
            g.Children.Add(boxSmall);
            svi.Content = g;

            window.IconDisplay.Items.Add(svi);

            DoubleAnimation animation = new DoubleAnimation();
            animation.From = 0.0;
            animation.To = 1.0;
            animation.Duration = new Duration(TimeSpan.FromSeconds(3));
            animation.AutoReverse = false;

            Storyboard storyboard = new Storyboard();
            storyboard.Children.Add(animation);
            Storyboard.SetTargetName(animation, boxSmall.Name);
            Storyboard.SetTargetProperty(animation, new PropertyPath(Viewbox.OpacityProperty));

            svi.SizeChanged += delegate(object s, SizeChangedEventArgs args)
            {
                if (args.NewSize.Width < 150 && args.NewSize.Height < 150)
                {
                    boxSmall.Visibility = System.Windows.Visibility.Visible;
                    box.Visibility = System.Windows.Visibility.Collapsed;
                    storyboard.Begin(this);
                }
            };

        }

private void Package\u ContactDown（对象发送方，ContactEventArgs e）
{
ScatterViewItem svi=新的ScatterViewItem（）；
svi.方向=0；
移除阴影（svi）；
svi.IsActive=true；
PackageView视图=新PackageView（源文件，此文件）；
view.SetCatterveItem（svi）；
svi.宽度=1024；
svi.高度=768；
svi.Center=新点（512384）；
Viewbox=新的Viewbox（）；
box.Child=视图；
Viewbox boxSmall=新的Viewbox（）；
boxsall.Name=“SmallLayout”；
TextBlock txt=新的TextBlock（）；
txt.Text=“类的包”；
boxsall.Child=txt；
boxsall.Visibility=System.Windows.Visibility.Collapsed；
不透明度=0；
boxsallow.ishitsetvisible=false；
网格g=新网格（）；
g、 添加（框）；
g、 添加（小方框）；
svi.Content=g；
window.IconDisplay.Items.Add（svi）；
DoubleAnimation=新的DoubleAnimation（）；
动画.From=0.0；
动画.To=1.0；
animation.Duration=新的持续时间（TimeSpan.FromSeconds（3））；
animation.AutoReverse=false；
情节提要情节提要=新情节提要（）；
故事板。儿童。添加（动画）；
Storyboard.SetTargetName（动画，boxsall.Name）；
Storyboard.SetTargetProperty（动画，新属性路径（Viewbox.OpacityProperty））；
svi.SizeChanged+=委托（对象s、SizeChangedEventArgs args）
{
if（args.NewSize.Width<150&&args.NewSize.Height<150）
{
boxsall.Visibility=System.Windows.Visibility.Visible；
box.Visibility=System.Windows.Visibility.Collapsed；
故事板。开始（这个）；
}
};
}

不幸的是，我经常遇到这样的异常：

System.InvalidOperationException was unhandled
  Message='SmallLayout' name cannot be found in the name scope of 'Prototype_Concept_2.views.DetailChooser'.
  Source=PresentationFramework
  StackTrace:
       at System.Windows.Media.Animation.Storyboard.ResolveTargetName(String targetName, INameScope nameScope, DependencyObject element)
       at System.Windows.Media.Animation.Storyboard.ClockTreeWalkRecursive(Clock currentClock, DependencyObject containingObject, INameScope nameScope, DependencyObject parentObject, String parentObjectName, PropertyPath parentPropertyPath, HandoffBehavior handoffBehavior, HybridDictionary clockMappings, Int64 layer)
       at System.Windows.Media.Animation.Storyboard.ClockTreeWalkRecursive(Clock currentClock, DependencyObject containingObject, INameScope nameScope, DependencyObject parentObject, String parentObjectName, PropertyPath parentPropertyPath, HandoffBehavior handoffBehavior, HybridDictionary clockMappings, Int64 layer)
       at System.Windows.Media.Animation.Storyboard.BeginCommon(DependencyObject containingObject, INameScope nameScope, HandoffBehavior handoffBehavior, Boolean isControllable, Int64 layer)
       at System.Windows.Media.Animation.Storyboard.Begin(FrameworkElement containingObject)
       at Prototype_Concept_2.views.DetailChooser.<>c__DisplayClass1.<Package_ContactDown>b__0(Object s, SizeChangedEventArgs args) in C:\Users\Roflcoptr\Documents\Visual Studio 2008\Projects\Prototype_Concept_2\Prototype_Concept_2\views\DetailChooser.xaml.cs:line 244
       at System.Windows.SizeChangedEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
       at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
       at System.Windows.FrameworkElement.OnRenderSizeChanged(SizeChangedInfo sizeInfo)
       at System.Windows.ContextLayoutManager.fireSizeChangedEvents()
       at System.Windows.ContextLayoutManager.UpdateLayout()
       at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
       at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()
       at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
       at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
       at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.DispatcherOperation.InvokeImpl()
       at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
       at System.Threading.ExecutionContext.runTryCode(Object userData)
       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Windows.Threading.DispatcherOperation.Invoke()
       at System.Windows.Threading.Dispatcher.ProcessQueue()
       at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
       at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
       at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.Run()
       at System.Windows.Application.RunDispatcher(Object ignore)
       at System.Windows.Application.RunInternal(Window window)
       at System.Windows.Application.Run(Window window)
       at System.Windows.Application.Run()
       at Prototype_Concept_2.App.Main() in C:\Users\Roflcoptr\Documents\Visual Studio 2008\Projects\Prototype_Concept_2\Prototype_Concept_2\obj\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

System.InvalidOperationException未处理
在“Prototype\u Concept\u 2.views.DetailChooser”的名称范围中找不到Message='SmallLayout'名称。
Source=PresentationFramework
堆栈跟踪：
位于System.Windows.Media.Animation.Storyboard.ResolveTargetName（字符串targetName、INameScope名称范围、DependencyObject元素）
在System.Windows.Media.Animation.Storyboard.ClockTreeWalkRecursive（时钟当前时钟、包含对象的DependencyObject、INameScope名称范围、DependencyObject父对象、字符串父对象名称、属性路径父属性路径、切换行为切换行为、混合字典时钟映射、Int64层）
在System.Windows.Media.Animation.Storyboard.ClockTreeWalkRecursive（时钟当前时钟、包含对象的DependencyObject、INameScope名称范围、DependencyObject父对象、字符串父对象名称、属性路径父属性路径、切换行为切换行为、混合字典时钟映射、Int64层）
位于System.Windows.Media.Animation.Storyboard.BeginCommon（DependencyObject包含对象、INameScope名称范围、切换行为切换行为、布尔值可控制、Int64层）
在System.Windows.Media.Animation.Storyboard.Begin（FrameworkElement包含对象）
在c:\Users\Roflcoptr\Documents\Visual Studio 2008\Projects\Prototype\u Concept\u 2\Prototype\u Concept\u 2\views\DetailChooser.xaml.cs第244行的Prototype\u Concept\u.views\DetailChooser
在System.Windows.SizeChangedEventArgs.InvokeeEventHandler（委托genericHandler，对象genericTarget）中
位于System.Windows.RouteDevenTargets.InvokeHandler（委托处理程序，对象目标）
位于System.Windows.RoutedEventHandlerInfo.InvokeHandler（对象目标，RoutedEventTargets RoutedEventTargets）
在System.Windows.EventRoute.InvokeHandlersImpl（对象源，RoutedEventArgs参数，布尔值重新调高）
位于System.Windows.UIElement.RaiseEventImpl（DependencyObject发送方，RoutedEventTargets参数）
在System.Windows.UIElement.RaiseEvent（RoutedEventArgs e）处
位于System.Windows.FrameworkElement.OnRenderSizeChanged（SizeChangedInfo sizeInfo）
位于System.Windows.ContextLayoutManager.fireSizeChangedEvents（）处
位于System.Windows.ContextLayoutManager.UpdateLayout（）处
位于System.Windows.ContextLayoutManager.UpdateLayoutCallback（对象参数）
位于System.Windows.Media.MediaContext.InvokeRenderCallback.DoWork（）处
在System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks（）中
位于System.Windows.Media.MediaContext.RenderMessageHandlerCore（对象大小调整的CompositionTarget）
位于System.Windows.Media.MediaContext.RenderMessageHandler（对象大小调整的CompositionTarget）
位于System.Windows.Threading.ExceptionWrapper.InternalRealCall（委托回调、对象参数、布尔isSingleParameter）
位于System.Windows.Threading.ExceptionWrapper.TryCatchWhen（对象源、委托回调、对象参数、布尔isSingleParameter、委托catchHandler）
位于System.Windows.Threading.Dispatcher.WrappedInvoke（委托回调、对象参数、布尔isSingleParameter、委托catchHandler）
在System.Windows.Threading.DispatcherOperation.InvokeImpl（）中
位于System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext（对象状态）
位于System.Threading.ExecutionContext.runTryCode（对象用户数据）
在System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup（TryCode代码、CleanupCode backoutCode、Object userData）中运行
位于System.Threading.ExecutionContext.RunInternal（ExecutionContext ExecutionContext，ContextCallback回调，对象状态）