>主MVC应用程序位于解决方案的根目录中.
>所有管理员功能都在一个单独的区域.
>每个外部方(如供应商)都有自己的区域.
>每个区域,包括根,构成一个很好的分离
功能块.一个区域的功能可能不会暴露
另一个区域.这是为了防止未经授权的访问数据.
>每个区域,都有自己的RESTfull API(Web API).
所有地区的所有正常控制器,按预期工作.但是,我的一些Web API控制器出现意外的行为.例如,具有两个具有相同名称但不同区域的Web API控制器产生以下异常：
Multiple types were found that match the controller named ‘clients’.
This can happen if the route that services this request
(‘api/{controller}/{id}’) found multiple controllers defined with the
same name but differing namespaces,which is not supported.The request for ‘clients’ has found the following matching controllers:
MvcApplication.Areas.Administration.Controllers.Api.ClientsController
MvcApplication.Controllers.Api.ClientsController
这似乎很奇怪,因为我有不同的路线应该分开两者.这是我的区域注册管理部分：
public class AdministrationAreaRegistration : AreaRegistration
{
public override string AreaName
{
get
{
return "Administration";
}
}
public override void RegisterArea(AreaRegistrationContext context)
{
context.Routes.MapHttpRoute(
name: "Administration_DefaultApi",routeTemplate: "Administration/api/{controller}/{id}",defaults: new { id = RouteParameter.Optional }
);
context.MapRoute(
"Administration_default","Administration/{controller}/{action}/{id}",new { action = "Index",id = UrlParameter.Optional }
);
}
}
此外,我注意到,我可以访问区域特定的Web API,同时省略来自呼叫的区域的名称.
这里发生了什么？
如何让我的Web API控制器的行为就像普通的ASP.NET MVC控制器一样？
解决方法
ASP.NET MVC 4 does not support the partitioning of Web API controllers across Areas.
您可以将WebApi控制器放在不同区域的不同Api文件夹中,但是ASP.NET MVC将会被视为处于同一个地方.
幸运的是,您可以通过覆盖ASP.NET MVC基础架构的一部分来克服此限制.有关限制和解决方案的更多信息,请阅读我的博客文章’ASP.NET MVC 4 RC: Getting WebApi and Areas to play nicely‘.如果您只对解决方案感兴趣,请继续阅读：
步骤1.使您的路线区域知道
将以下扩展方法添加到ASP.NET MVC应用程序,并确保它们可以从您的AreaRegistration类访问：
public static class AreaRegistrationContextExtensions
{
public static Route MapHttpRoute(this AreaRegistrationContext context,string name,string routeTemplate)
{
return context.MapHttpRoute(name,routeTemplate,null,null);
}
public static Route MapHttpRoute(this AreaRegistrationContext context,string routeTemplate,object defaults)
{
return context.MapHttpRoute(name,defaults,object defaults,object constraints)
{
var route = context.Routes.MapHttpRoute(name,constraints);
if (route.DataTokens == null)
{
route.DataTokens = new RouteValueDictionary();
}
route.DataTokens.Add("area",context.AreaName);
return route;
}
}
context.MapHttpRoute( /* <-- .Routes removed */
name: "Administration_DefaultApi",defaults: new { id = RouteParameter.Optional }
);
步骤2.使Web API控制器选择器区域感知
将以下类添加到您的ASP.NET MVC应用程序,并确保它可以从Global.asax访问
namespace MvcApplication.Infrastructure.Dispatcher
{
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net.Http;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Dispatcher;
public class AreaHttpControllerSelector : DefaultHttpControllerSelector
{
private const string AreaRouteVariableName = "area";
private readonly HttpConfiguration _configuration;
private readonly Lazy<ConcurrentDictionary<string,Type>> _apiControllerTypes;
public AreaHttpControllerSelector(HttpConfiguration configuration)
: base(configuration)
{
_configuration = configuration;
_apiControllerTypes = new Lazy<ConcurrentDictionary<string,Type>>(GetControllerTypes);
}
public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
return this.GetApiController(request);
}
private static string GetAreaName(HttpRequestMessage request)
{
var data = request.GetRouteData();
if (data.Route.DataTokens == null)
{
return null;
}
else
{
object areaName;
return data.Route.DataTokens.TryGetValue(AreaRouteVariableName,out areaName) ? areaName.ToString() : null;
}
}
private static ConcurrentDictionary<string,Type> GetControllerTypes()
{
var assemblies = AppDomain.CurrentDomain.GetAssemblies();
var types = assemblies
.SelectMany(a => a
.GetTypes().Where(t =>
!t.IsAbstract &&
t.Name.EndsWith(ControllerSuffix,StringComparison.OrdinalIgnoreCase) &&
typeof(IHttpController).IsAssignableFrom(t)))
.ToDictionary(t => t.FullName,t => t);
return new ConcurrentDictionary<string,Type>(types);
}
private HttpControllerDescriptor GetApiController(HttpRequestMessage request)
{
var areaName = GetAreaName(request);
var controllerName = GetControllerName(request);
var type = GetControllerType(areaName,controllerName);
return new HttpControllerDescriptor(_configuration,controllerName,type);
}
private Type GetControllerType(string areaName,string controllerName)
{
var query = _apiControllerTypes.Value.AsEnumerable();
if (string.IsNullOrEmpty(areaName))
{
query = query.WithoutAreaName();
}
else
{
query = query.ByAreaName(areaName);
}
return query
.ByControllerName(controllerName)
.Select(x => x.Value)
.Single();
}
}
public static class ControllerTypeSpecifications
{
public static IEnumerable<KeyValuePair<string,Type>> ByAreaName(this IEnumerable<KeyValuePair<string,Type>> query,string areaName)
{
var areaNameToFind = string.Format(CultureInfo.InvariantCulture,".{0}.",areaName);
return query.Where(x => x.Key.IndexOf(areaNameToFind,StringComparison.OrdinalIgnoreCase) != -1);
}
public static IEnumerable<KeyValuePair<string,Type>> WithoutAreaName(this IEnumerable<KeyValuePair<string,Type>> query)
{
return query.Where(x => x.Key.IndexOf(".areas.",StringComparison.OrdinalIgnoreCase) == -1);
}
public static IEnumerable<KeyValuePair<string,Type>> ByControllerName(this IEnumerable<KeyValuePair<string,string controllerName)
{
var controllerNameToFind = string.Format(CultureInfo.InvariantCulture,".{0}{1}",AreaHttpControllerSelector.ControllerSuffix);
return query.Where(x => x.Key.EndsWith(controllerNameToFind,StringComparison.OrdinalIgnoreCase));
}
}
}
通过将以下行添加到Global.asax中的Application_Start方法来覆盖DefaultHttpControllerSelector.
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector),new AreaHttpControllerSelector(GlobalConfiguration.Configuration));
恭喜,您的Web API控制器现在将像您正常的MVC控制器一样尊重您所在区域的规则！
更新：2012年9月6日
几位开发人员已经联系了我们关于路由变量的DataTokens属性为空的遇到的情况.我的实现假定DataTokens属性始终是初始化的,如果此属性为空,则它将无法正常运行.这种行为很可能是由于ASP.NET MVC框架中最近的变化而引起的,可能实际上是框架中的一个错误.我已经更新了我的代码来处理这种情况.
