Question

I am using a WebBrowser component in WPF to host some JavaScript + HTML and I want to be able to pass a customisable object in as the ObjectForScripting property. My end goal is that the javascript running in the WebBrowser can call something like:

window.external['lookup'].getValue(someId);

I can achieve something close to this by implementing a class with ComVisible set to true that has a lookup property on it:

[ComVisible(true)]
public class ScriptingContext
{
    public LookupService lookup { get; set; } //where LookupService is also ComVisible
}

However, I want to be flexible about the members on the ObjectForScripting that I’m passing in so I can’t specify what each property will be beforehand.

Ideally I would like to just specify a name-object pair to pass in, but afaict this doesn’t work.

What I have tried (and failed with) so far:

• using a Dictionary<string,object> as my context
• using an extension of Dictionary<string,object> that is marked as ComVisible
• using an ExpandoObject
• using a List<KeyValuePair<string,object>>
• using an extension of List<KeyValuePair<string,object>> that is marked as ComVisible

Is there some way to pass a customisable ObjectForScripting into the WPF WebBrowser that I am missing?

Answer 1

I’m not sure what you mean by customisable, but there’s plenty of ways to accomplish what you’re going for, such as building a wrapper for your dictionary and having that be your ObjectForScripting:

[ComVisible(true)] 
public class ScriptingContext 
{
    private Dictionary<string, object> objectsForScripting;
    public object GetValue(string s) 
    {
        return objectsForScripting[s];
    }
}

With the corresponding javascript window.external.GetValue("lookup").getValue(someId).

Note that you can also pass ComVisible objects to javascript through the InvokeScript method and interact with them that way, using something like webBrowser.InvokeScript("RegisterProperty", "lookup", lookupObject) and manage the objects you’re exposing on the javascript side.