Action过滤器使用实例(一)

1.实例一

    /// <summary>
    ///  需要用户登陆的 action，执行提前验证
    /// </summary>
    public class LoginFilterAttribute : FilterAttribute, IActionFilter
    {
        void IActionFilter.OnActionExecuted(ActionExecutedContext filterContext)
        {
        }
        /// <summary>
        /// 执行action 前验证 用户是否登陆，如果没有登陆返回字符串体质
        /// </summary>
        /// <param name="filterContext"></param>
        void IActionFilter.OnActionExecuting(ActionExecutingContext filterContext)
        {
            // throw new NotImplementedException();
            //1.判断
            if (A_UserHelper.IsLogin() == false)
            {
                ContentResult result = new ContentResult();
                result.Content = "亲，还没有登陆，请先登录";
                filterContext.Result = result;
            }
        }

    }

2.实例二

    public class LoginGoAttribute : FilterAttribute, IActionFilter
    {
        void IActionFilter.OnActionExecuted(ActionExecutedContext filterContext)
        {
            //throw new NotImplementedException();
        }
        /// <summary>
        /// 执行action 之前 验证用户是否登陆，如果没有登陆返回登陆页面
        /// </summary>
        /// <param name="filterContext"></param>
        void IActionFilter.OnActionExecuting(ActionExecutingContext filterContext)
        {
            //throw new NotImplementedException();
            if (A_UserHelper.IsLogin() == false)
            {
                //不跳转在当前地址返回登陆页------
                //RouteData route = filterContext.RouteData;
                //route.Values["controller"] = "user";
                //route.Values["action"] = "login";
                //IController IController = new UserController();
                //HttpContextBase context = filterContext.HttpContext;
                //IController.Execute(new RequestContext(context, route));
                //filterContext.Result = new ContentResult();

                //重定向到登陆页--------不推荐使用，因为当前action还是会执行
                //HttpContextBase context = filterContext.HttpContext;
                //context.Response.Redirect(SiteUrl.GetLogin(),true);
                //context.Response.End();
                //filterContext.ActionDescriptor = null;

                //临时重定向到登陆页
                HttpRequestBase req = filterContext.HttpContext.Request;
                string url = SiteUrl.GetLogin() + "?redirecturl=" + req.Url.AbsoluteUri;
                RedirectResult result = new RedirectResult(url, false);
                filterContext.Result = result;

                //此方法 失败
                //HttpContextBase context = filterContext.HttpContext;
                //UserController userC = new UserController();
                //userC.ControllerContext = new ControllerContext();
                //userC.ControllerContext.RouteData.DataTokens["controller"] = "user";
                //userC.ControllerContext.RouteData.Values["area"] = "";
                //ContentResult content = new ContentResult();
                //content.Content = ViewHelper.RenderViewToString(userC, "login", null); ;
                //filterContext.Result = content;

            }
        }
    }

更多：

MVC4过滤器：http://www.cnblogs.com/tianma3798/p/4666544.html