Add missing field declaration and namespace for AbpDynamicFormTagHelper

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpDynamicformTagHelper.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
@@ -21,6 +22,8 @@ public class AbpDynamicFormTagHelper : AbpTagHelper<AbpDynamicFormTagHelper, Abp
     public bool? RequiredSymbols { get; set; } = true;
 
     #region MvcFormTagHelperAttiributes
+    
+    private IDictionary<string, string> _routeValues;
 
     private const string ActionAttributeName = "asp-action";
     private const string AreaAttributeName = "asp-area";