设置WebApi里面命名空间参数

在这种情况下：



如果没有特别处理，会报：



所以要像MVC中的控制器一下配置一个命名空间参数，webapi里面没有自带这个功能

代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;
using System.Web.Http.Dispatcher;
using AutoData.Utility;

namespace AutoData
{
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
config.MapHttpAttributeRoutes();
//config.HostNameComparisonMode = HostNameComparisonMode.Exact;

config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);

config.Routes.MapHttpRoute(
name: "Admin Area Default",
routeTemplate: "api/admin/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional, namespaceName = "AutoData.Areas.Admin.Controllers"  }
);

config.Routes.MapHttpRoute(
name: "IndustryInsight Area Default",
routeTemplate: "Api/IndustryInsight/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);

config.Routes.MapHttpRoute(
name: "ComputeFormula Area Default",
routeTemplate: "Api/ComputeFormula/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional , namespaceName = "AutoData.Areas.ComputeFormula.Controllers"}
);
config.Services.Replace(typeof(IHttpControllerSelector), new NamespaceHttpControllerSelector(config));
}
}
}

最后一句设置，也可以配置在全局类里面：

GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector), new NamespaceHttpControllerSelector(GlobalConfiguration.Configuration));

功能是一样的

NamespaceHttpConrollerSelector类

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Dispatcher;
using System.Web.Http.Routing;

namespace AutoData.Utility
{
public class NamespaceHttpControllerSelector : IHttpControllerSelector
{
private const string NamespaceKey = "namespaceName";
private const string ControllerKey = "controller";

private readonly HttpConfiguration _configuration;
private readonly Lazy<Dictionary<string, HttpControllerDescriptor>> _controllers;
private readonly HashSet<string> _duplicates;

public NamespaceHttpControllerSelector(HttpConfiguration config)
{
_configuration = config;
_duplicates = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
_controllers = new Lazy<Dictionary<string, HttpControllerDescriptor>>(InitializeControllerDictionary);
}

private Dictionary<string, HttpControllerDescriptor> InitializeControllerDictionary()
{
var dictionary = new Dictionary<string, HttpControllerDescriptor>(StringComparer.OrdinalIgnoreCase);

// Create a lookup table where key is "namespace.controller". The value of "namespace" is the last
// segment of the full namespace. For example:
// MyApplication.Controllers.V1.ProductsController => "V1.Products"
IAssembliesResolver assembliesResolver = _configuration.Services.GetAssembliesResolver();
IHttpControllerTypeResolver controllersResolver = _configuration.Services.GetHttpControllerTypeResolver();

ICollection<Type> controllerTypes = controllersResolver.GetControllerTypes(assembliesResolver);

foreach (Type t in controllerTypes)
{
var segments = t.Namespace.Split(Type.Delimiter);

// For the dictionary key, strip "Controller" from the end of the type name.
// This matches the behavior of DefaultHttpControllerSelector.
var controllerName = t.Name.Remove(t.Name.Length - DefaultHttpControllerSelector.ControllerSuffix.Length);

//var key = String.Format(CultureInfo.InvariantCulture, "{0}.{1}", segments[segments.Length - 1], controllerName); //旧版本
var key = String.Format(CultureInfo.InvariantCulture, "{0}.{1}", t.Namespace.ToString(), controllerName);    //新版本

// Check for duplicate keys.
if (dictionary.Keys.Contains(key))
{
_duplicates.Add(key);
}
else
{
dictionary[key] = new HttpControllerDescriptor(_configuration, t.Name, t);
}
}

// Remove any duplicates from the dictionary, because these create ambiguous matches.
// For example, "Foo.V1.ProductsController" and "Bar.V1.ProductsController" both map to "v1.products".
foreach (string s in _duplicates)
{
dictionary.Remove(s);
}
return dictionary;
}

// Get a value from the route data, if present.
private static T GetRouteVariable<T>(IHttpRouteData routeData, string name)
{
object result = null;
if (routeData.Values.TryGetValue(name, out result))
{
return (T)result;
}
return default(T);
}

public HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
IHttpRouteData routeData = request.GetRouteData();
if (routeData == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}

// Get the namespace and controller variables from the route data.
string namespaceName = GetRouteVariable<string>(routeData, NamespaceKey);
if (namespaceName == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}

string controllerName = GetRouteVariable<string>(routeData, ControllerKey);
if (controllerName == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}

// Find a matching controller.
string key = String.Format(CultureInfo.InvariantCulture, "{0}.{1}", namespaceName, controllerName);

HttpControllerDescriptor controllerDescriptor;
if (_controllers.Value.TryGetValue(key, out controllerDescriptor))
{
return controllerDescriptor;
}
else if (_duplicates.Contains(key))
{
throw new HttpResponseException(
request.CreateErrorResponse(HttpStatusCode.InternalServerError,
"Multiple controllers were found that match this request."));
}
else
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
}

public IDictionary<string, HttpControllerDescriptor> GetControllerMapping()
{
return _controllers.Value;
}
}
}

对它进行了一点点的修改，

旧版本的命名空间选.号的最后一个

我设置的取全名命名空间

这样设置以后会发现一起没有设置命名空间的路由会发生错误，所有WebApiConfig里面的路由必须设置命名空间
http://www.cnblogs.com/nikyxxx/p/3356659.html http://aspnet.codeplex.com/SourceControl/changeset/view/dd207952fa86#Samples/WebApi/NamespaceControllerSelector/NamespaceHttpControllerSelector.cs http://www.osdo.net/article/2015/01/13/160.html http://blog.csdn.net/starfd/article/details/41728655