Question

Is it possible to make a filter that, after a controller action has been (mostly) processed, checks for a certain test condition and routes to a different view transparently to the user (i.e., no change in the URL)?

Here would be my best guess at some pseudocode:

    public override void OnResultExecuting(ResultExecutingContext filterContext)
    {
        // If some condition is true
        //  Change the resulting view resolution to XYZ

        base.OnResultExecuting(filterContext);
    }

Answer 1

filterContext.Result = new ViewResult
{
    ViewName = "~/Views/SomeController/SomeView.cshtml"
};

This will short-circuit the execution of the action.