// 登录认证特性
public class AuthenticationAttribute : ActionFilterAttribute
{public override void OnActionExecuting(ActionExecutingContext filterContext){if (filterContext.HttpContext.Session["username"] == null)filterContext.Result = new RedirectToRouteResult("Login", new RouteValueDictionary { { "from", Request.Url.ToString() } });base.OnActionExecuting(filterContext);}
}

public class HomeController : Controller
{ [Authentication] public ActionResult Index(){return View();}
}

public class MvcApplication : System.Web.HttpApplication
{protected void Application_Start(){AreaRegistration.RegisterAllAreas();WebApiConfig.Register(GlobalConfiguration.Configuration); FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);RouteConfig.RegisterRoutes(RouteTable.Routes);}
}

public class FilterConfig
{public static void RegisterGlobalFilters(GlobalFilterCollection filters){filters.Add(new HandleErrorAttribute()); filters.Add(new AuthenticationAttribute());}
}

public class AuthenticationControllor : Controller
{public bool Validate(){if (Session["username"] == null)return false;elsereturn true;}public ActionResult RedirectLogin(bool redirect = true){if (redirect)return RedirectToAction("Login", "Home", new { from = Request.Url.ToString() });elsereturn RedirectToAction("Login", "Home");}
}

public class HomeController : AuthenticationControllor
{public ActionResult Index(){if (!Validate())return RedirectLogin();return View();}
}

public class AuthenticationControllor : Controller
{protected override void OnActionExecuting(ActionExecutingContext filterContext){if (filterContext.HttpContext.Session["username"] == null)filterContext.Result = new RedirectToRouteResult("Login", new RouteValueDictionary { { "from", Request.Url.ToString() } });base.OnActionExecuting(filterContext);}
}

// 不需要多写任何逻辑代码就能判断是否登录并跳转
public class HomeController : AuthenticationControllor
{public ActionResult Index(){ return View();}
}

/// <summary>/// 权限拦截/// </summary>[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false)]public class PermissionFilterAttribute : ActionFilterAttribute{/// <summary>/// 权限拦截/// </summary>/// <param name="filterContext"></param>public override void OnActionExecuting(ActionExecutingContext filterContext){if (!this.CheckAnonymous(filterContext)){//未登录验证if (SessionHelper.Get("UserID") == null){//跳转到登录页面filterContext.RequestContext.HttpContext.Response.Redirect("~/Admin/User/Login");}}}/// <summary>/// [Anonymous标记]验证是否匿名访问/// </summary>/// <param name="filterContext"></param>/// <returns></returns>public bool CheckAnonymous(ActionExecutingContext filterContext){//验证是否是匿名访问的Actionobject[] attrsAnonymous = filterContext.ActionDescriptor.GetCustomAttributes(typeof(AnonymousAttribute), true);//是否是Anonymousvar Anonymous = attrsAnonymous.Length == 1;return Anonymous;}}

/// <summary>/// Admin后台系统公共控制器(需要验证的模块)/// </summary>
    [PermissionFilter]public class BaseController:Controller{}