/// <summary>
 /// 启用FastApi处理框架
 /// </summary>
 /// <param name="builder"></param>
 /// <param name="router"></param>
 /// <returns></returns>
 public static IAppBuilder UseFastWebApi(this IAppBuilder builder, IWebApiRouter router)
 {
     return(builder.Use <WebApiMiddleware>(router));
 }
 /// <summary>
 /// 构造函数,第一个参数必须为 OwinMiddleware对象
 /// </summary>
 /// <param name="next">下一个中间件</param>
 public WebApiMiddleware(OwinMiddleware next, IWebApiRouter router) : base(next)
 {
     _router = router;
     _next   = next;
 }