Added GetFirstGenericArgumentIfNullable extension method

framework/src/Volo.Abp.Core/Volo/Abp/Reflection/TypeHelper.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Reflection;
 
 namespace Volo.Abp.Reflection
@@ -33,8 +34,8 @@ namespace Volo.Abp.Reflection
                 return true;
             }
 
-            if (includeNullables && 
-                type.IsGenericType && 
+            if (includeNullables &&
+                type.IsGenericType &&
                 type.GetGenericTypeDefinition() == typeof(Nullable<>))
             {
                 return IsPrimitiveExtendedInternal(type.GenericTypeArguments[0], includeEnums);
@@ -43,6 +44,16 @@ namespace Volo.Abp.Reflection
             return false;
         }
 
+        public static Type GetFirstGenericArgumentIfNullable(this Type t)
+        {
+            if (t.GetGenericArguments().Length > 0 && t.GetGenericTypeDefinition() == typeof(Nullable<>))
+            {
+                return t.GetGenericArguments().FirstOrDefault();
+            }
+
+            return t;
+        }
+
         private static bool IsPrimitiveExtendedInternal(Type type, bool includeEnums)
         {
             if (type.IsPrimitive)

framework/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/EntityHistory/EntityHistoryHelper.cs

@@ -13,6 +13,7 @@ using Volo.Abp.DependencyInjection;
 using Volo.Abp.Domain.Entities;
 using Volo.Abp.Json;
 using Volo.Abp.MultiTenancy;
+using Volo.Abp.Reflection;
 using Volo.Abp.Timing;
 using Volo.Abp.Uow;
 
@@ -170,7 +171,7 @@ namespace Volo.Abp.EntityFrameworkCore.EntityHistory
                         NewValue = isDeleted ? null : JsonSerializer.Serialize(propertyEntry.CurrentValue).TruncateWithPostfix(EntityPropertyChangeInfo.MaxValueLength),
                         OriginalValue = isCreated ? null : JsonSerializer.Serialize(propertyEntry.OriginalValue).TruncateWithPostfix(EntityPropertyChangeInfo.MaxValueLength),
                         PropertyName = property.Name,
-                        PropertyTypeFullName = property.ClrType.FullName,
+                        PropertyTypeFullName = property.ClrType.GetFirstGenericArgumentIfNullable().FullName,
                         TenantId = GetTenantId(entityEntry.Entity)
                     });
                 }
@@ -311,7 +312,7 @@ namespace Volo.Abp.EntityFrameworkCore.EntityHistory
                                     NewValue = JsonSerializer.Serialize(propertyEntry.CurrentValue),
                                     OriginalValue = JsonSerializer.Serialize(propertyEntry.OriginalValue),
                                     PropertyName = property.Name,
-                                    PropertyTypeFullName = property.ClrType.FullName
+                                    PropertyTypeFullName = property.ClrType.GetFirstGenericArgumentIfNullable().FullName
                                 });
                             }