先分析需求
在MVC项目中，我们如果有两个Areas。比如Test和DEMO。我们的访问地址应该是
http://localhost:8098/test
http://localhost:8098/demo
如果我们绑定域名后想实现这样访问
http://test.abc.com:8098/
http://demo.abc.com:8098/
这个问题的相关解决办法倒是不少，比如http://www.cnblogs.com/jobily/archive/2011/10/09/2204800.html。可惜都是破坏了原来项目的结构，对于已经上线的项目不太适用。
本文的解决办法实在不破坏原来的结构之上，在原来的Areas里面重新绑定新的路由规则，重写基类路由 RouteBase的GetRouteData方法达到绑定二级域名，访问Areas的方法。
前期准备工作你需要先修改本地host文件，绑定一些二级域名。比如
127.0.0.1 demo.abc.com
127.0.0.1 test.abc.com
首先新建 AreaDomainRegistrationContext类。
public class AreaDomainRegistrationContext ???{ ???????/// <summary> ???????/// ???????/// </summary> ???????/// <param name="_domainName">子域名 如:www.xxx.com 可以传 abc</param> ???????public AreaDomainRegistrationContext(AreaRegistrationContext _context, string _domainName) ???????{ ???????????domainName = _domainName; context = _context; ???????} ???????private string domainName; private AreaRegistrationContext context; ???????private RouteCollection Routes ???????{ ???????????get ???????????{ ???????????????if (!DomainRouteTable.DomainRoutes.ContainsKey(domainName)) ???????????????{ ???????????????????DomainRouteTable.DomainRoutes[domainName] = new RouteCollection(); ???????????????} ???????????????return DomainRouteTable.DomainRoutes[domainName]; ???????????} ???????} ???????public Route MapRoute(string name, string url, object defaults, object constraints = null, string[] namespaces = null) ???????{ ???????????if (namespaces == null && context.Namespaces != null) ???????????{ ???????????????namespaces = context.Namespaces.ToArray(); ???????????} ???????????Route route = Routes.MapRoute(name, url, defaults, constraints, namespaces); ???????????route.DataTokens["area"] = context.AreaName; ???????????route.DataTokens["UseNamespaceFallback"] = false; ???????????route.DataTokens["SubDomain"] = domainName; ???????????return route; ???????} ???}DomainRouteTable类里面有一个静态属性DomainRoutes。主要存储域名和路由之间的存储关联。
public class DomainRouteTable ???{ ???????private static Dictionary<string, RouteCollection> _instance = new Dictionary<string, RouteCollection>(); ???????public static Dictionary<string, RouteCollection> DomainRoutes ???????{ ???????????get ???????????{ ???????????????return _instance; ???????????} ???????} ???}下面就是重写RouteBase的类了
public class DomainRoute : RouteBase ???{ ???????public ResolveDomainName resolveDomainName = DependencyResolver.Current.GetService<ResolveDomainName>(); ???????public RouteData d = new RouteData(null, new StopRoutingHandler()); ???????public override RouteData GetRouteData(HttpContextBase httpContext) ???????{ ???????????string domainName = resolveDomainName.Resolve(httpContext); ???????????//该主机头没有配置，返回 null 继续查找路由 ???????????if (domainName == null) return null; ???????????if (!DomainRouteTable.DomainRoutes.ContainsKey(domainName)) return d; ???????????var rs = DomainRouteTable.DomainRoutes[domainName]; ???????????RouteData routeData = rs.GetRouteData(httpContext); ???????????if (routeData == null) return d; ???????????return routeData; ???????} ???????public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values) ???????{ ???????????string domainName = resolveDomainName.Resolve(requestContext.HttpContext); ???????????if (domainName == null) return null; ???????????if (!DomainRouteTable.DomainRoutes.ContainsKey(domainName)) return null; ???????????var rs = DomainRouteTable.DomainRoutes[domainName]; ???????????VirtualPathData vpd = rs.GetVirtualPathForArea(requestContext, values); ???????????return vpd; ???????} ???}ResolveDomainName主要映射Areas和域名之间的关系，可以根据Areas查找到域名。
public class ResolveDomainName ???{ ???????public static Dictionary<string, string> DomainMap = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); ???????public string Resolve(HttpContextBase httpContext) ???????{ ???????????string key = httpContext.Request.Headers["host"]; ???????????string value; ???????????if (DomainMap.TryGetValue(key, out value)) { return value; } ???????????else return null; ???????} ???}接下来在Global文件的里面的Application_Start方法里面的第一行加入一下代码
RouteTable.Routes.Add(new DomainRoute());
???????????ResolveDomainName.DomainMap.Add("demo.abc.com:8098", "demo1");
ResolveDomainName.DomainMap.Add("test.abc.com:8098", "Test");
这样就可以绑定多个域名，后面的demo1和Test可以不和areas的名称相等，这里这是一个key而已。
接着在Areas区域里面绑定路由的地方加入一下代码
var context2 = new AreaDomainRegistrationContext(context, "Test"); ???????????context2.MapRoute( ???????????????name: "Test_default", ???????????????url: "{controller}/{action}", ???????????????defaults: new { controller = "Home", action = "index" }, ??????????????namespaces: new string[] { "WebApplication1.Areas.Test.Controllers" });代码看起来是这样的，这样并不影响之前的访问，还是可以通过areas的方式访问的
同理demo区域也添加代码。
接着编译我们的项目，就可以用demo.abc.com:8098来访问了，是不是很简单。
访问后的效果
本文参考文章地址
https://www.cnblogs.com/hitearth/p/6848788.html
asp.net ?MVC把Areas区域绑定成二级域名
原文地址：https://www.cnblogs.com/Playfunny/p/9875342.html