InvalidOperationException: “System.Windows.Media.Animation.DoubleAnimation”动画对象不能用于动画属性“StartPoint”，因为它是不兼容的类型“System.Windows.Point”。
StackTrace:
   在 System.Windows.Media.Animation.Storyboard.VerifyAnimationIsValid(DependencyProperty targetProperty, AnimationClock animationClock)
   在 System.Windows.Media.Animation.Storyboard.ProcessComplexPath(HybridDictionary clockMappings, DependencyObject targetObject, PropertyPath path, AnimationClock animationClock, HandoffBehavior handoffBehavior, Int64 layer)
   在 System.Windows.Media.Animation.Storyboard.ClockTreeWalkRecursive(Clock currentClock, DependencyObject containingObject, INameScope nameScope, DependencyObject parentObject, String parentObjectName, PropertyPath parentPropertyPath, HandoffBehavior handoffBehavior, HybridDictionary clockMappings, Int64 layer)
   在 System.Windows.Media.Animation.Storyboard.ClockTreeWalkRecursive(Clock currentClock, DependencyObject containingObject, INameScope nameScope, DependencyObject parentObject, String parentObjectName, PropertyPath parentPropertyPath, HandoffBehavior handoffBehavior, HybridDictionary clockMappings, Int64 layer)
   在 System.Windows.Media.Animation.Storyboard.BeginCommon(DependencyObject containingObject, INameScope nameScope, HandoffBehavior handoffBehavior, Boolean isControllable, Int64 layer)
   在 System.Windows.Media.Animation.Storyboard.Begin()
   在 DynamicClass.cc.<>c__DisplayClass5b.<<初始化>b__3f>d__86.MoveNext()
--- 引发异常的上一位置中堆栈跟踪的末尾 ---
   在 System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   在 System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   在 System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)