WebApi多版本控制

常用的解决方案

①不同版本不同域名；
②在url、报文头等中带不同版本信息，用NginX做反向代理服务器，然后将http://api.xx.com/api/v1/Usr/1和http://api.xx.com/api/v2/Usr/1转到不同服务器
③多个版本的controller在一个项目中，然而使用[RoutePrefix]或者IHttpControllerSeletor根据报文头、路径等信息选择不同的Controller执行。

eg:

[RoutePrefix("api/v2/Hoo")]
    public class HomeController : ApiController
    {
        [Route("Get")]
        public string Get() {
            return "测试一下";
        }
    }

//一旦设置了[RoutePrefix]、[Route],在路由表中的路由就当前Controller失去了管理。

通过自定义ControllerSelector实现多版本管理

　　1.修改路由

　　　　

config.Routes.MapHttpRoute(
                name: "DefaultApiv1",
                routeTemplate: "api/v1/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
            config.Routes.MapHttpRoute(
                name: "DefaultApiv2",
                routeTemplate: "api/v2/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

 

　　2.自定义VersionControllerSelector类继承DefaultHttpControllerSelector，重写GetControllerMapping、SelectController

　　

public class VersionControllerSelector : DefaultHttpControllerSelector
    {
        private HttpConfiguration config;
        private IDictionary<string, HttpControllerDescriptor> mCtrlMapping;
        public VersionControllerSelector(HttpConfiguration config) : base(config)
        {
            this.config = config;
        }
        /// <summary>
        /// 获取所有的controller，并注册
        /// </summary>
        /// <returns></returns>
        public override IDictionary<string, HttpControllerDescriptor> GetControllerMapping()
        {
            Dictionary<string, HttpControllerDescriptor> dict = new Dictionary<string, HttpControllerDescriptor>();
            foreach (var asm in config.Services.GetAssembliesResolver().GetAssemblies())
            {
                //获取继承自ApiController的非抽象类
                var controllerTypes = asm.GetTypes()
                    .Where(e => !e.IsAbstract && typeof(ApiController).IsAssignableFrom(e)).ToArray();
                //获取controller的名字
                foreach (var ctrlType in controllerTypes)
                {
                    string ctrlTypeNs = ctrlType.Namespace;
                    var match = Regex.Match(ctrlTypeNs, @"\.v(\d+)");
                    if (match.Success)
                    {
                        string verNum = match.Groups[1].Value;//把版本号中的数字提取出来
                        string ctrlTypeName = ctrlType.Name;//controller名字
                        var matchController = Regex.Match(ctrlTypeName, @"^(.+)Controller$");
                        if (!matchController.Success)
                        {
                            continue;
                        }
                        string ctrlName = matchController.Groups[1].Value;
                        string key = ctrlName + "v" + verNum;//个性约定
                        dict[key] = new HttpControllerDescriptor(config, ctrlName, ctrlType);
                    }
                }
                mCtrlMapping=dict;
            }
            return dict;
        }

        /// <summary>
        /// 返回HttpControllerDescriptor的过程
        /// </summary>
        /// <param name="request"></param>
        /// <returns></returns>
        public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
        {
            string controller = (string)request.GetRouteData().Values["controller"];
            if (mCtrlMapping == null) {
                mCtrlMapping = GetControllerMapping();
            }
            
            var matchVer = Regex.Match(request.RequestUri.PathAndQuery, @"/v(\d+)/");
            if (!matchVer.Success)
            {
                return base.SelectController(request);
            }
            string verNum = matchVer.Groups[1].Value;
            string key = controller + "v" + verNum;
            if (mCtrlMapping.ContainsKey(key))
            {
                return mCtrlMapping[key];
            }
            else
            {
                return base.SelectController(request);
            }
        }
    }

 

　　3.在config中注册注册VersionControllerSelector类

　　config.Services.Replace(typeof(IHttpControllerSelector), new VersionControllerSelector(config));