RuntimeBinderException: “DynamicClass”未包含“ToJson”的定义
StackTrace:
   在 CallSite.Target(Closure , CallSite , Object , Boolean )
   在 System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)
   在 DynamicClass.OnMenuItemClick(Object sender, RoutedEventArgs e)
   在 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   在 System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   在 System.Windows.Controls.MenuItem.InvokeClickAfterRender(Object arg)
   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)