更改不是子动作的Controller内的ViewBag，并在View上下文中检索它

Question

Our application has a global Controller that all other Controllers inherit from; from within, in the OnResultExecuting override, I access an item (something obtained by accessing the Session, the HttpContext and the Web.config) that I store in the

filterContext.ParentActionViewContext.ViewBag

and this allows me to access this item in the ViewBag later in the lifecycle of the request.

PROBLEM : some of those filterContext are NOT child Action, and as such their ParentActionViewContext field is null, and I don't know of any other way to access the ViewBag.

QUESTION : if my controller stumbles upon a non-child Action, how can I still pass this item to the ViewBag?

I would like to stress my inexperience with ASP.Net MVC4 - if there is a better way to approach this same problem, please do not hesitate to suggest it.

EDIT: adding some code for clarification.

This is where I save myItem in the ViewBag in my Controller method:

protected override void OnResultExecuting(ResultExecutingContext filterContext) {

    [...]

    if (filterContext.ParentActionViewContext != null && filterContext.ParentActionViewContext.ViewBag != null) {
        filterContext.ParentActionViewContext.ViewBag["DealerId"] = myItem;
    }

    [...]

    base.OnResultExecuting(filterContext);
}

And this is where I retrieve it inside my HtmlHelper:

public static MvcHtmlString DealerSpecificLessStyleSheet(this HtmlHelper htmlHelper)
    {
        var linkBuilder = new TagBuilder("link");

        var dealerReferenceGuid = (string)htmlHelper.ViewBag["DealerId"];
        /* Do something with this ID */

        [...]
        return new MvcHtmlString(linkBuilder.ToString());
    }

Answer 1

I access an item (something obtained by accessing the Session...

If you already have the value in Session then you don't need to have it in the ViewBag just specifically in your current situation. You can use a helper class to get it to your views:

public sealed class UIHelper
{
    public static string GetThatValue()
    {
        return (string)HttpContext.Current.Session["target_key"];
    }
}