diff --git a/src/IGeekFan.AspNetCore.Knife4jUI/Knife4UIBuilderExtensions.cs b/src/IGeekFan.AspNetCore.Knife4jUI/Knife4UIBuilderExtensions.cs
index 8f22498..5cc7910 100644
--- a/src/IGeekFan.AspNetCore.Knife4jUI/Knife4UIBuilderExtensions.cs
+++ b/src/IGeekFan.AspNetCore.Knife4jUI/Knife4UIBuilderExtensions.cs
@@ -2,29 +2,36 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
-
+using Microsoft.AspNetCore.Hosting;
+#if NETSTANDARD2_0
+using IWebHostEnvironment = Microsoft.AspNetCore.Hosting.IHostingEnvironment;
+#endif
 
 namespace IGeekFan.AspNetCore.Knife4jUI
 {
     public static class Knife4UIBuilderExtensions
     {
+        public static IApplicationBuilder UseKnife4UI(this IApplicationBuilder app, Knife4UIOptions options)
+        {
+            return app.UseMiddleware<Knife4jUIMiddleware>(options);
+        }
         public static IApplicationBuilder UseKnife4UI(
              this IApplicationBuilder app,
              Action<Knife4UIOptions> setupAction = null)
         {
             var options = new Knife4UIOptions();
-            if (setupAction != null)
+            using (var scope = app.ApplicationServices.CreateScope())
             {
-                setupAction(options);
+                options = scope.ServiceProvider.GetRequiredService<IOptionsSnapshot<Knife4UIOptions>>().Value;
+                setupAction?.Invoke(options);
             }
-            else
-            {
-                options = app.ApplicationServices.GetRequiredService<IOptions<Knife4UIOptions>>().Value;
-            }
-            
-            app.UseMiddleware<Knife4jUIMiddleware>(options);
 
-            return app;
+            if (options.ConfigObject.Urls == null)
+            {
+                var hostingEnv = app.ApplicationServices.GetRequiredService<IWebHostEnvironment>();
+                options.ConfigObject.Urls = new[] { new UrlDescriptor { Name = $"{hostingEnv.ApplicationName} v1", Url = "v1/swagger.json" } };
+            }
+            return app.UseKnife4UI(options);
         }
     }
 }