Javascript calling C# function under SliverLight

Question

I have a SilverLight application using C#, with 2 main functions that I want to make accessible from JavaScript functions. I have done the RegisterScriptableObject() in the class and set-up the [ScriptableMember] for the functions I want access to.

This the SilverLight object:

<div id="silverlightControlHost">
 <object id="silverlightControl" data="data:application/x-silverlight," type="application/x-silverlight-2" width="1024px" height="300px">
  <param name="source" value="DrawingWaveForm.xap"/>
  <param name="onerror" value="onSilverlightError" />
  <param name="background" value="white" />
  <param name="minRuntimeVersion" value="2.0.31005.0" />
  <param name="autoUpgrade" value="true" />
  <a href="http://go.microsoft.com/fwlink/?LinkID=124807" style="text-decoration: none;">
      <img src="http://go.microsoft.com/fwlink/?LinkId=108181" alt="Get Microsoft Silverlight" style="border-style: none"/>
  </a>
 </object>
 <iframe style='visibility:hidden;height:0;width:0;border:0px'></iframe>
</div>

and these are my JavaScript functions:

 function Start()
    {
        var control = document.getElementById("silverlightControl");            
        control.Content.Page.Start();
    }

 function Stop()
    {
        var control = document.getElementById("silverlightControl");            
        control.Content.Page.Stop();
    }

Can anyone tell me where I'm going wrong as it does not seem to work

Answer 1

It's just a thought but do you perhaps need to make the methods public (they don't appear to be in your code)?

Answer 2

You need to ensure your C# functions are marked as Scriptable. See http://silverlight.net/learn/learnvideo.aspx?video=65683 for some walk throughs on how to accomplish this.

Answer 3

As timheuer said, [Scriptable] on your Silverlight methods.

Call this in your class:

HtmlPage.RegisterScriptableObject("Page", this);

Call the Silverlight methods marked as Scriptable from your javascript like this:

function CenterMap(latitude, longitude)
{
     var silvercontrol = document.getElementById("ctl00_cphMain_slControl");
     if (silvercontrol)
     silvercontrol.Content.Page.CenterOnCoordinates(latitude, longitude);
}

This page shows you this and how to do the reverse, calling javascript methods from Silverlight. It's a really nice model.

Answer 4

I was just hammering against this problem myself. The first js function works, but everything else throws this error. After tinkering around, I noticed that changing the underlying C# function that was working successfully was having no impact -- the browser was working with a cached version of the Silverlight control. Try clearing your browser's cache.

Answer 5

Would it be the same problem that was answered at this link? Javascript to Silverlight when Silverlight instanciated with object tag