ActionExecutingContext 返回结果

protected override void OnActionExecuting(ActionExecutingContext filterContext)
{

    string action = RouteData.GetRequiredString("action").ToLower();
    switch (action)
    {
                
      case "index":
      filterContext.Result = Redirect("Url");
      break;
      default:
      base.OnActionExecuting(filterContext);
      break;
    }
}