Policy要继承IPolicy

CloudBuilder/CloudBuilder.Security/Policy/FileTypePolicy.cs

@@ -1,5 +1,6 @@
 using CloudBuilder.Core.DatabaseAccessor.Entity;
 using CloudBuilder.Core.DependencyInjection.Form;
+using CloudBuilder.Core.DependencyInjection.Policy;
 using CloudBuilder.Core.DependencyInjection.Request;
 using CloudBuilder.Core.Policy;
 using Microsoft.Extensions.DependencyInjection;
@@ -11,7 +12,7 @@ using System.Threading.Tasks;
 
 namespace CloudBuilder.Security.Policy
 {
-    public class FileTypePolicy : AbstractPolicy
+    public class FileTypePolicy : AbstractPolicy, IPolicy
     {
         public const string VIDEO = "V";
         public const string AUDIO = "A";