Calling Javascript Object Method in a System.Windows.Forms.WebBrowser Contorl

WebBrowserExtensions.cs

using System;
using System.Linq;
using System.Web.Script.Serialization;
using System.Windows.Forms;

namespace AsynchronousWebPage
{
    /// <summary>
    ///     Extension convenience methods to invoke arbitrary Javascript method on a web page
    ///     hosted by a WebBrowser control.
    ///     This extensions makes use of the <see cref="System.Web.Script.Serialization.JavaScriptSerializer" />
    ///     object to serialise objects to JSON. You might need to add a reference to the
    ///     System.Web.Extensions assembly.
    /// </summary>
    public static class WebBrowserExtensions
    {
        /// <summary>
        ///     Invoke an arbitrary Javascript function on a hosted web page
        ///     Beware of the pitfall of calling this before a document has loaded: https://msdn.microsoft.com/en-us/library/cc491132.aspx
        /// </summary>
        /// <param name="browser">The WebBrowser control</param>
        /// <param name="function">The name of the Javascript function to execute. For example, "object.foobar"</param>
        /// <param name="argObjects">An array containing arguments to the function. The arguments will be serialised to JSON.</param>
        /// <returns>The result from the Javascript function, if any.</returns>
        public static Object InvokeScript(this WebBrowser browser, string function, params object[] argObjects)
        {
            var javaScriptSerializer = new JavaScriptSerializer();
            var args = String.Join(",",
                argObjects.Select(o => javaScriptSerializer.Serialize(o)));
            const string script = "{0}({1});";
            return browser.InvokeScript(String.Format(script, function, args));
        }

        /// <summary>
        ///     Invoke arbitrary Javascript code on a hosted web page
        ///     Beware of the pitfall of calling this before a document has loaded: https://msdn.microsoft.com/en-us/library/cc491132.aspx
        /// </summary>
        /// <param name="browser">The WebBrowser control</param>
        /// <param name="script">Arbitrary Javascript code</param>
        /// <returns>The result from the Javascript function, if any.</returns>
        public static Object InvokeScript(this WebBrowser browser, string script)
        {
            if (browser.Document == null)
            {
                throw new InvalidOperationException("There is no document loaded in the WebBrowser control");
            }
            // Ugly workaround: http://stackoverflow.com/questions/7322420/
            var selfExecutingScript = @"(function () { 'use strict'; function execute() { " + script +
                                      @" } return execute(); }());";
            // We can only call the InvokeScript method in the thread that owns the WebBrowser control.
            // Thus, we have to execute this via delegate using the Invoke method on the browser control.
            var action =
                new Func<object>(() => browser.Document.InvokeScript("eval", new object[] {selfExecutingScript}));
            return browser.Invoke(action);
        }
    }
}