WebApi支持命名空间重名问题

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Dispatcher;
using System.Web.Http.Routing;

namespace ZQNB.Common.Web.Api
{
//针对WebApi的扩展
//目的是为了让WebApi支持命名空间的筛选
//程序启动时，替换IHttpControllerSelector选择器
//GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector), new NamespaceHttpControllerSelector(GlobalConfiguration.Configuration));

public static class HttpRouteCollectionEx
{
public static IHttpRoute MapHttpRoute(this HttpRouteCollection routes, string name, string routeTemplate, object defaults, string[] namespaces)
{
return routes.MapHttpRoute(name, routeTemplate, defaults, null, null, namespaces);
}
public static IHttpRoute MapHttpRoute(this HttpRouteCollection routes, string name, string routeTemplate, object defaults, object constraints, HttpMessageHandler handler, string[] namespaces)
{
if (routes == null)
{
throw new ArgumentNullException("routes");
}
var routeValue = new HttpRouteValueDictionary(new { Namespace = namespaces });//设置路由值
var route = routes.CreateRoute(routeTemplate, new HttpRouteValueDictionary(defaults), new HttpRouteValueDictionary(constraints), routeValue, handler);
routes.Add(name, route);
return route;
}
}

public class NamespaceHttpControllerSelector : DefaultHttpControllerSelector
{
private const string NamespaceRouteVariableName = "Namespace";
private readonly HttpConfiguration _configuration;
private readonly Lazy<ConcurrentDictionary<string, Type>> _apiControllerCache;

public NamespaceHttpControllerSelector(HttpConfiguration configuration)
: base(configuration)
{
_configuration = configuration;
_apiControllerCache = new Lazy<ConcurrentDictionary<string, Type>>(new Func<ConcurrentDictionary<string, Type>>(InitializeApiControllerCache));
}

private ConcurrentDictionary<string, Type> InitializeApiControllerCache()
{
IAssembliesResolver assembliesResolver = this._configuration.Services.GetAssembliesResolver();
var types = this._configuration.Services.GetHttpControllerTypeResolver().GetControllerTypes(assembliesResolver).ToDictionary(t => t.FullName, t => t);

return new ConcurrentDictionary<string, Type>(types);
}

public IEnumerable<string> GetControllerFullName(HttpRequestMessage request, string controllerName)
{
object namespaceName;
var apiControllerKeys = Enumerable.Empty<string>();
string[] namespaces = null;
var data = request.GetRouteData();
IEnumerable<string> allApiControllers = _apiControllerCache.Value.ToDictionary(t => t.Key,
t => t.Value, StringComparer.CurrentCultureIgnoreCase).Keys.ToList();
namespaces = (string[]) this.GetRouteValue(NamespaceRouteVariableName, data);

if (namespaces != null && namespaces.Any())
{
var area = (string) this.GetRouteValue("area", data);
if (!string.IsNullOrEmpty(area))
{
for (int i = 0; i < namespaces.Length; i++)
{
if (namespaces[i].Contains("{area}"))
{
namespaces[i] = namespaces[i].Replace("{area}", area);
}
}
}

return from n in namespaces
join k in allApiControllers on
string.Format("{0}.{1}{2}", n, controllerName, DefaultHttpControllerSelector.ControllerSuffix)
.ToLower() equals k.ToLower()
select k;
}
//get the defined namespace
return allApiControllers.Where(
k =>
k.EndsWith(
string.Format(".{0}{1}", controllerName, DefaultHttpControllerSelector.ControllerSuffix),
StringComparison.CurrentCultureIgnoreCase));
}

private object GetRouteValue(string key, IHttpRouteData httpRouteData)
{
object value;
if (httpRouteData.Route.DataTokens != null &&
httpRouteData.Route.DataTokens.TryGetValue(key, out value))
{
if (value != null)
{
return value;
}

}
if (httpRouteData.Values != null && httpRouteData.Values.TryGetValue(key, out value))
{
if (value != null)
{
return value;
}
}
return null;
}

public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
Type type;
if (request == null)
{
throw new ArgumentNullException("request");
}
string controllerName = this.GetControllerName(request);
if (string.IsNullOrEmpty(controllerName))
{
throw new HttpResponseException(request.CreateErrorResponse(HttpStatusCode.NotFound,
string.Format("No route providing a controller name was found to match request URI '{0}'", new object[] { request.RequestUri })));
}
IEnumerable<string> fullNames = GetControllerFullName(request, controllerName);
var enumerable = fullNames as string[] ?? fullNames.ToArray();
if (!enumerable.Any())
{
throw new HttpResponseException(request.CreateErrorResponse(HttpStatusCode.NotFound,
string.Format("No route providing a controller name was found to match request URI '{0}'", new object[] { request.RequestUri })));
}

//如果能匹配上多个，排除优先选择不在限制内的命名空间
if (this._apiControllerCache.Value.TryGetValue(enumerable.First(), out type))
{
return new HttpControllerDescriptor(_configuration, controllerName, type);
}
throw new HttpResponseException(request.CreateErrorResponse(HttpStatusCode.NotFound,
string.Format("No route providing a controller name was found to match request URI '{0}'", new object[] { request.RequestUri })));
}
}
}

最后Global

//设置我们自己的 ControllerFactory
ControllerBuilder.Current.SetControllerFactory(new NbDefaultControllerFactory(CoreServiceProvider.Current.GetAllInstances<IControllerProvider>()));
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector), new NamespaceHttpControllerSelector(GlobalConfiguration.Configuration));