I'm trying to answer this post and I got one issue that I think it is a bug.

What I'm trying to do is that trying to pass one value to Javascript function from Managed Code. As there is no parameter in EventArgs class, I created new class with parameter.It is working fine. then, The problem is that the property that I created "T Data" is not shown in Javascript. another thing that I notice is that sender is always null even we are sending the object.

The new EventArgs class with parameters

public class EventArgs<T> : EventArgs{
        private T _data;

        public EventArgs(T args)
        {
            _data = args;
        }

        public T Data
        {
            get
            {
                return _data;
            }           
        }
    }

Page.xaml.cs

[Scriptable]
    public partial class Page : Canvas {

        public Page() {
         
            WebApplication.Current.RegisterScriptableObject("EntryPoint", this);           
            MouseLeftButtonDown += Page_MouseLeftButtonDown;
        }
        void Page_MouseLeftButtonDown(object sender, MouseEventArgs e) {
            if (CallbackToBrowser != null) {
                CallbackToBrowser(this, new EventArgs<string>("my value"));
            }
        }

        [Scriptable]
        public event EventHandler CallbackToBrowser;

    }

TestPage.html.js

// JScript source code

//contains calls to silverlight.js, example below loads Page.xaml
function createSilverlight()
{
    Silverlight.createObjectEx({
        source: "Page.xaml",
        parentElement: document.getElementById("SilverlightControlHost"),
        id: "SilverlightControl",
        properties: {
            width: "100%",
            height: "100%",
            version: "1.1",
            enableHtmlAccess: "true"
        },
        events: {
           onLoad: OnLoaded
        }
    });
      
    // Give the keyboard focus to the Silverlight control by default
    document.body.onload = function() {
      var silverlightControl = document.getElementById('SilverlightControl');
      if (silverlightControl)
      silverlightControl.focus();
    }
}
function OnLoaded(sender, args)
{
    sender.Content.EntryPoint.CallbackToBrowser = onManagedCallback;
}

function onManagedCallback(sender, args)
{
    if(args.Data){                                              //ERROR is here. args is nothing. sender is null.
        alert(args.Data);
    }  
}
 

Is that a bug or Did I miss something in my code? Thanks in advance.  

(If this has answered your question, please click on "Mark as Answer" on this post. Thank you!)

Best Regards,
Michael Sync

Microsoft WPF & Silverlight Insider
Blog : http://michaelsync.net

I am not sure why the sender is always null, that might be a bug.  But the bigger issue is the event argument.  To fix this you must mark the EventArgs as scriptable:

  [Scriptable]
  public class EventArgs<T> : EventArgs
  {
    private T _data;

    public EventArgs(T args)
    {
      _data = args;
    }

    [Scriptable]
    public T Data
    {
      get
      {
        return _data;
      }
    }
  }

HTH

(If this has answered your question, "Mark as Answer")

Shawn Wildermuth
C# MVP, MCSD, Speaker and Author

Silverlight 2 and 3 Workshop
Boston, MA: April 29 - May 1
Washington, DC: June 16-18th
http://silverlight-tour.com

thanks. 

(If this has answered your question, please click on "Mark as Answer" on this post. Thank you!)

Best Regards,
Michael Sync

Microsoft WPF & Silverlight Insider
Blog : http://michaelsync.net