Embedding a JS file in Silverlight Class Library

Question

I am trying to create a Silverlight class library which needs to call a few Javascript methods. I have put these methods in a single .js file and have added it to the project. But when I try to call any of the methods in the js file, I get a FailedtoInvoke error. I understand that this problem can be solved by adding a reference of the JS file in the head section of ASPX or HTML page. But I am developing a class library and so that is not possible. Does someone know how to tackle this issue? I am using Silverlight 4 and Visual Studio 2010.

Answer 1

Add the .js file to your library probject as it sounds you have done, make sure it Build Action is "Resource".

You can retrieve this content with Application.GetResourceStream :-

StreamResourceInfo sriJS = Application.GetResourceStream(new Uri("YourAssemblyName;component/MyStuff.js", UriKind.Relative));

Note the structure of the Uri, the assembly name of your class library is needed followed by the literal ";component". This tells Silverlight to look for a resource inside your dll that will be included in a final application's Xap.

Now you need to turn the content of the info's Stream property into a string:-

StreamReader reader = new StreamReader(sriJS.Stream, System.Text.Encoding.UTF8);
string js = reader.ReadToEnd();

Finally you can inject that javascript into the current page with:-

HtmlPage.Window.Eval(js);

Thats it, any global functions defined in the js may now be invoked with HtmlPage.Window.Invoke.

Answer 2

Try something like:

string myScriptCodeString = GetScriptCodeStringFromSomewhere();
System.Windows.Browser.HtmlPage.Window.Eval(myScriptCodeString);

Then the methods defined in myScriptCodeString should be available.