求教这段WPF中嵌入Flash的代码哪里出有关问题了？

求教这段WPF中嵌入Flash的代码哪里出问题了？？？
为什么使用底下这种动态添加控件的方式来嵌入Flash会出现问题？？
  //创建一个边框（最外层）
  Border borderBody = new Border();
  borderBody.Background = Brushes.Transparent;
  borderBody.BorderBrush = Brushes.White;
  borderBody.BorderThickness = new Thickness(5);
   
  //创建一个滚动条(放到最外层边框去)
  ScrollViewer scroll = new ScrollViewer();
  scroll.Width = 1160;
  scroll.Height = 104;
  scroll.HorizontalScrollBarVisibility = ScrollBarVisibility.Hidden;
  scroll.VerticalScrollBarVisibility = ScrollBarVisibility.Hidden;
  scroll.Background = Brushes.Transparent;
  borderBody.Child = scroll; //放到边框去

  //创建一个StackPanel容器用来保存具体元素（放到滚动条内）
  StackPanel sp = new StackPanel();
  sp.Height = 104;
  sp.Orientation = Orientation.Horizontal;
  scroll.Content = sp; //放到滚动条去

  //具体元素放到StackPanel
  for (int i = 0; i < 100; i++)
  {
  Border border = new Border();
  border.BorderBrush = Brushes.White;
  border.BorderThickness = new Thickness(2);
  border.Width = 100;
  border.Height = 75;

  WindowsFormsHost formHost = new WindowsFormsHost();

  AxShockwaveFlash axShockwaveFlash = new AxShockwaveFlash();

  formHost.Child = axShockwaveFlash;

  border.Child = formHost;

  //出错
  //引发类型为“System.Windows.Forms.AxHost+InvalidActiveXStateException”的异常。
  axShockwaveFlash.Movie = @"E:\game.swf";  

  sp.Children.Add(border);
  }

  //最后将最外层边框添加到界面去
  grid.Children.Add(borderBody);



奇怪的是为什么这样就不会出问题
StackPanel sp = new StackPanel();

Border border = new Border();
border.BorderBrush = Brushes.White;
border.BorderThickness = new Thickness(2);
border.Width = 100;
border.Height = 75;

WindowsFormsHost formHost = new WindowsFormsHost();

AxShockwaveFlash axShockwaveFlash = new AxShockwaveFlash();

formHost.Child = axShockwaveFlash;

border.Child = formHost;

sp.Children.Add(border);

grid.Children.Add(sp);

axShockwaveFlash.Movie = @"E:\game.swf";


------解决方案--------------------
好像wpf加入activex控件 窗口不能设透明