/// <summary>
 /// 使用ApiExplorer引擎生成doc.json
 /// </summary>
 /// <param name="app"></param>
 /// <param name="routeTemplate">路由模板,默认“{version}/doc.json”,version为必须路由参数</param>
 /// <param name="setupAction"></param>
 /// <returns></returns>
 public static HttpApplication UseApiExplorer(this HttpApplication app, Action <ApiExplorerUIOptions> setupAction, string routeTemplate = "{version}/doc.json")
 {
     return(app
            .UseApiExplorerGenerator(routeTemplate)
            .UseApiExplorerUI(setupAction));
 }