silverlight与JavaScript交互，WebApplication在哪里?该如何解决

silverlight与JavaScript交互，WebApplication在哪里?
RT，找不到WebApplication啊，使用WebApplication.Current.RegisterScriptableObject后，
显示：找不到类型或命名空间名称“WebApplication”(是否缺少 using 指令或程序集引用?)
请问如何才能使用这个类啊~

[解决办法]
使用 [Scriptable] 属性了么？

试试这样写代码：

C# code

using System;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Ink;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using System.Windows.Browser;namespace ClientSideAndServerSide {    [Scriptable]    public class EventArgs<T> : EventArgs {        private T _data;        public EventArgs(T args) {            _data = args;        }        [Scriptable]        public T Data {            get {                return _data;            }        }    }    [Scriptable]    public partial class Page : Canvas {        [Scriptable]        public event EventHandler CallbackToBrowser;        public void Page_Loaded(object o, EventArgs e) {            // Required to initialize variables            InitializeComponent();            WebApplication.Current.RegisterScriptableObject("EntryPoint", this);              this.MouseLeftButtonDown += new MouseEventHandler(Page_MouseLeftButtonDown);        }        void Page_MouseLeftButtonDown(object sender, MouseEventArgs e) {            if (CallbackToBrowser != null) {                CallbackToBrowser(this, new EventArgs<string>("my value"));            }        }    }}