基于空项目模板创建使用Owin来host的WebApi项目

首先创建一个空的web项目，如下图所示：

项目创建成功以后，安装下面三个package.

Install-Package Microsoft.AspNet.WebApi -Version 5.2.2
Install-Package Microsoft.AspNet.WebApi.Owin -Version 5.2.2
Install-Package Microsoft.Owin.Host.SystemWeb -Version 3.0.0

创建Owin Startup 类

 using System;
 using System.Threading.Tasks;
 using Microsoft.Owin;
 using Owin;
 using System.Web.Http;

 [assembly: OwinStartup(typeof(FirstOwinWebApi.Startup))]

 namespace FirstOwinWebApi
 {
     public class Startup
     {
         public void Configuration(IAppBuilder app)
         {
             HttpConfiguration config = new HttpConfiguration();

             // Web API routes
             config.MapHttpAttributeRoutes();

             //WebApiConfig.Register(config);

             app.UseWebApi(config);
         }
     }
 }

创建API Controller.

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Web.Http;

 namespace FirstOwinWebApi.Controllers
 {
     [RoutePrefix("api/HelloWorld")]
     public class HelloWorldController : ApiController
     {
         [Route("")]
         public IHttpActionResult Post()
         {

             return Ok<string>("Hello World");

         }

     }
 }

F5运行，使用Postman访问Api

其他一些Owin中间件包：

Install-Package Microsoft.AspNet.WebApi -Version 5.2.2

Install-Package Microsoft.AspNet.WebApi.Owin -Version 5.2.2

Install-Package Microsoft.Owin.Host.SystemWeb -Version 3.0.0

Install-Package Microsoft.Owin.Cors -Version 3.0.0

Install-Package Microsoft.Owin.Security.OAuth -Version 3.0.0

Install-Package Microsoft.Owin.Security.Jwt -Version 3.0.0

Install-Package System.IdentityModel.Tokens.Jwt -Version 4.0.0

Install-Package Thinktecture.IdentityModel.Core Version 1.2.0

Install-Package Microsoft.AspNet.Identity.Owin -Version 2.0.1

Install-Package Microsoft.AspNet.Identity.EntityFramework -Version 2.0.1