Question

I use an anonymous object to pass my Html Attributes to some helper methods.
If the consumer didn’t add an ID attribute, I want to add it in my helper method.

How can I add an attribute to this anonymous object?

Answer 1

If you’re trying to extend this method:

public static MvcHtmlString ActionLink(this HtmlHelper htmlHelper, string linkText, string actionName, object routeValues);

Although I’m sure Khaja’s Object extensions would work, you might get better performance by creating a RouteValueDictionary and passing in the routeValues object, add your additional parameters from the Context, then return using the ActionLink overload that takes a RouteValueDictionary instead of an object:

This should do the trick:

    public static MvcHtmlString MyLink(this HtmlHelper helper, string linkText, string actionName, object routeValues)
    {
        RouteValueDictionary routeValueDictionary = new RouteValueDictionary(routeValues);

        // Add more parameters
        foreach (string parameter in helper.ViewContext.RequestContext.HttpContext.Request.QueryString.AllKeys)
        {
            routeValueDictionary.Add(parameter, helper.ViewContext.RequestContext.HttpContext.Request.QueryString[parameter]);
        }

        return helper.ActionLink(linkText, actionName, routeValueDictionary);
    }