DotNetBrowser 2.9

browser.Navigation.LoadProgressChanged += (s, e) =>
{
    //The value indicating the loading progress of the web page.
    double progress = e.Progress;
};

browser.Mouse.Pressed.Handler =
    new Handler<IMousePressedEventArgs, InputEventResponse>(e =>
    {
        if (e.Button == MouseButton.Back || e.Button == MouseButton.Forward)
        {
            return InputEventResponse.Suppress;
        }
        else
        {
            return InputEventResponse.Proceed;
        }
    });

browser.Mouse.Released.Handler =
    new Handler<IMouseReleasedEventArgs, InputEventResponse>(e =>
    {
        if (e.Button == MouseButton.Back || e.Button == MouseButton.Forward)
        {
            return InputEventResponse.Suppress;
        }
        else
        {
            return InputEventResponse.Proceed;
        }
    });

IJsObject document = Browser.MainFrame.ExecuteJavaScript<IJsObject>("document").Result;
Dictionary<string, string> dictionary = new Dictionary<string, string>
{
    {"key1", "value1"}, 
    {"key2", "value2"}
};
document.Properties["dotNetDictionary"] = dictionary;

var value = document.dotNetDictionary["key1"];