MVC中使用AuthorizeAttribute身份验证

代码顺序为：OnAuthorization-->AuthorizeCore-->HandleUnauthorizedRequest

如果AuthorizeCore返回false时，才会走HandleUnauthorizedRequest
方法，并且Request.StausCode会返回401，401错误又对应了Web.config中

所有，AuthorizeCore==false
时，会跳转到 web.config 中定义的 loginUrl="

login/login"

AuthorizeAttribute的OnAuthorization方法内部调用了AuthorizeCore方法，这个方法是实现验证和授权逻辑的地方，如果这个方法返回true，表示授权成功，如果返回false， 表示授权失败，会给上下文设置一个HttpUnauthorizedResult，这个ActionResult执行的结果是向浏览器返回一个401状态码（未授权）,但是返回状态码没什么意思，通常是跳转到一个登录页面，可以重写AuthorizeAttribute的HandleUnauthorizedRequest

<authentication mode="Forms">
<forms loginUrl="login/login" timeout="2880" />
</authentication>

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false)]

    public class UserAuthorizeAttribute : AuthorizeAttribute

    {

        protected override bool AuthorizeCore(HttpContextBase httpContext)

        {

            var user = (SysUser)httpContext.Session["CurrentUser"];

            return user != null;

        }

        protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)

        {

            if (filterContext.HttpContext.Request.IsAjaxRequest())

            {

                var a = new JsonResult();

                a.Data = new AjaxResult() { Message = "会话已过期，请重新登录" };

                filterContext.Result = a;

                return;

            }

            filterContext.Result = new RedirectResult("/Login/Login?url=" + filterContext.HttpContext.Request.Url);

        }

    }