版本控制

版本控制的方法有很多，這裏提供一種將Odata與普通web api版本控制機制統一的方法，但也可以單獨控制，整合控制與單獨控制主要的不同是：整合控制通過VersionControllerSelector來選擇控制器過濾器，而不是直接選擇控制器。

采用此機制來控制版本，應按照如下規則命名控制器：

自定義標識符+版本+Controller

自定義標識符：能體現控制器含義的字符串

版本：表示版本的字符串，例如：V1，V1.0；不建議使用V1.0這樣的寫法，因為這樣控制器名稱會相當怪異，如果表示小版本號，那麽可以使用V1D0，這種寫法，即用一個字母代替句號。

命名空間對應了項目文件的組織形式

1 Odata版本控制

擴展DefaultHttpControllerSelector

public class ODataVersionControllerSelector : DefaultHttpControllerSelector
{
        public Dictionary<string, string> RouteVersionSuffixMapping { get; set; }

        public ODataVersionControllerSelector(HttpConfiguration configuration)
            : 
 
base(configuration)
        {
            if (RouteVersionSuffixMapping == null)
            {
                RouteVersionSuffixMapping = new Dictionary<string, string>();
            }
        }

        public override string GetControllerName(HttpRequestMessage request)
        {
            
 
var controllerName = base.GetControllerName(request);
            if (string.IsNullOrEmpty(controllerName))
            {
                return controllerName;
            }

            var routeName = request.ODataProperties().RouteName;
            if (string.IsNullOrEmpty(routeName))
            {
                return controllerName;
            }

            var mapping = GetControllerMapping();

            if (!RouteVersionSuffixMapping.ContainsKey(routeName))
            {
                return controllerName;
            }

            var versionControllerName = controllerName + RouteVersionSuffixMapping[routeName];
            return mapping.ContainsKey(versionControllerName)
                ? versionControllerName
                : controllerName;
        }
}

修改WebApiConfig.Register方法

public static class WebApiConfig
{
　　public static void Register(HttpConfiguration config)
　　{
　　　　　　......

　　　　　　//odata路由
            config.MapODataServiceRoute(
                           routeName: "V1OdataRouteVersioning",
                           routePrefix: "Odata/V1",
                           model: GetEdmModel());
            config.Count().Filter().OrderBy().Expand().Select().MaxTop(null);
            config.AddODataQueryFilter();

            config.Services.Replace(typeof(IHttpControllerSelector), new ODataVersionControllerSelector (config));
            var controllerSelector = config.Services.GetService(typeof(IHttpControllerSelector)) as ODataVersionControllerSelector ;
　　　　　　　controllerSelector.RouteVersionSuffixMapping.Add("V1OdataRouteVersioning", "V1");

　　　　　　　　......
　　}
}

private static IEdmModel GetEdmModel()
{
　　ODataConventionModelBuilder builder = new ODataConventionModelBuilder();
　　#region Publication
　　var publicationsSet = builder.EntitySet<Publication>("Publications").EntityType.Collection;
　　var getPublicationsFunction = publicationsSet.Function("GetPublications").Returns<PublicationDTO>();
　　getPublicationsFunction.Parameter<int>("userId");

   publicationsSet.Action("AddPublication").Returns<int>().Parameter<PublicationAddBindingModel>("publicationAddBM");
　　publicationsSet.Action("DeletePublication").Returns<IHttpActionResult>().Parameter<PublicationDelBindingModel>("publicationDelBM");
   #endregion

　　builder.Namespace = "Service";
　　return builder.GetEdmModel();
}

2 普通Api版本控制

擴展IHttpControllerSelector

public class NormalVersionControllerSelector : IHttpControllerSelector
{
        private const string Version = "version";
        private const string ControllerKey = "controller";

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

        public NormalVersionControllerSelector(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);

            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);

                //去掉HY_WebApi.V1.Controllers.KeyController中的HY_WebApi.
                //去掉HY_WebApi.HYDB.V1.Controllers.HYSearchController中的HY_WebApi.HYDB.
                //因此，保留V1.Controllers.KeyController這三部分
                //鍵值格式如：V1.Controllers.KeyController
                string[] items = t.FullName.Split(new char[]{‘.‘},StringSplitOptions.RemoveEmptyEntries);
                int count = items.Count();
                var key = string.Format("{0}.{1}.{2}", items[count - 3], items[count - 2], items[count - 1]);

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

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

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

            // 匹配控制器
            string key = String.Format("{0}.Controllers.{1}{2}Controller", version, controllerName,version);

            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;
        }
    }
}

修改WebApiConfig.Register方法

public static class WebApiConfig
{
        public static void Register(HttpConfiguration config)
        {

　　　　　　　　　　......

　　　　　　　　// Web API 路由
            config.Routes.MapHttpRoute(
                name: "defaultRoute",
                routeTemplate: "api/{version}/{controller}/{action}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
            config.Services.Replace(typeof(IHttpControllerSelector), new NormalVersionControllerSelector(config));
 
　　　　　　　　......

　　　　　}
}

3 同時支持Odata，與普通Web Api版本控制

擴展DefaultHttpControllerSelector

public class VersionControllerSelector : DefaultHttpControllerSelector
{
        public Dictionary<string, string> RouteVersionSuffixMapping { get; set; }
        private HttpConfiguration configuration;
        public VersionControllerSelector(HttpConfiguration configuration)
            : base(configuration)
        {
            this.configuration = configuration;
            if (RouteVersionSuffixMapping == null)
            {
                RouteVersionSuffixMapping = new Dictionary<string, string>();
            }
        }
        public override string GetControllerName(HttpRequestMessage request)
        {
            return SelectController(request).ControllerName;
        }

        public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
        {
            var routeName = request.ODataProperties().RouteName;

            if (!string.IsNullOrWhiteSpace(routeName))
            {//odata路由
                var selector = new ODataVersionControllerSelector(configuration);
                selector.RouteVersionSuffixMapping = RouteVersionSuffixMapping;
                return selector.SelectController(request);
            }
            else
            {//普通路由
                var selector = new NormalVersionControllerSelector(configuration);
                return selector.SelectController(request);
            }
        }
}

修改WebApiConfig.Register方法
public static class WebApiConfig

        public static void Register(HttpConfiguration config)
        {
　　　　　　　　// Web API 路由
            config.Routes.MapHttpRoute(
                name: "defaultRoute",
                routeTemplate: "api/{version}/{controller}/{action}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            //odata路由
            config.MapODataServiceRoute(
                           routeName: "V1OdataRouteVersioning",
                           routePrefix: "Odata/V1",
                           model: GetEdmModel());
            config.Count().Filter().OrderBy().Expand().Select().MaxTop(null);
            config.AddODataQueryFilter();

            config.Services.Replace(typeof(IHttpControllerSelector), new VersionControllerSelector(config));
            var controllerSelector = config.Services.GetService(typeof(IHttpControllerSelector)) as VersionControllerSelector;
            controllerSelector.RouteVersionSuffixMapping.Add("V1OdataRouteVersioning", "V1");
　　　　}
}

其中GetEdmModel()方法與前述方法相同。

asp.net web api 版本控制