主要思路
添加一个Attribute以及Filter类，在Filter中根据是否存在Attribute来判断是否跳到站点维护页。
代码实现
Attribute：
???/// <summary> ???/// ?站点关闭时也可访问 ???/// </summary> ???[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)] ???public class RunWhenSitePausedAttribute : Attribute ???{ ???}Filter：
???/// <summary> ???/// 站点是否开启过滤器 ???/// </summary> ???public class PauseSiteCheckFilter : IAuthorizationFilter, ITransientDependency ???{ ???????public void OnAuthorization(AuthorizationContext filterContext) ???????{ ???????????if (filterContext == null) ???????????{ ???????????????throw new ArgumentNullException("filterContext"); ???????????} ???????????if (filterContext.IsChildAction) ???????????????return; ???????????//判断是否进入站点维护页 ???????????if (!isEnable)//获取后台设置，如果站点关闭则进入以下判断 ???????????{ ???????????????var context = HttpContext.Current; ???????????????var methodInfo = filterContext.ActionDescriptor.GetMethodInfoOrNull(); ???????????????var isDefined = CanRunWhenSitePaused(methodInfo); ???????????????if (!isDefined) ???????????????{ ???????????????????//跳转页面 ???????????????????var url = UrlHelper.GenerateUrl(null, "PausePage", "Home", new RouteValueDictionary { { "area", "" } }, ???????????????????????RouteTable.Routes, context.Request.RequestContext, true); ???????????????????filterContext.Result = new RedirectResult(url); ???????????????} ???????????} ???????} ???????/// <summary> ???????/// 检查是否存在[RunWhenSitePaused]属性 ???????/// </summary> ???????/// <param name="methodInfo"></param> ???????/// <param name="defaultValue"></param> ???????/// <returns></returns> ???????private bool CanRunWhenSitePaused(MethodInfo methodInfo, bool defaultValue = false) ???????{ ???????????if (methodInfo == null) ???????????{ ???????????????return false; ???????????} ???????????if (!methodInfo.IsPublic) ???????????{ ???????????????return false; ???????????} ???????????if (methodInfo.IsDefined(typeof(RunWhenSitePausedAttribute), true)) ???????????{ ???????????????return true; ???????????} ???????????var classType = methodInfo.DeclaringType; ???????????if (classType != null) ???????????{ ???????????????if (classType.IsDefined(typeof(RunWhenSitePausedAttribute), true)) ???????????????{ ???????????????????return true; ???????????????} ???????????} ???????????return defaultValue; ???????} ???}