Avoid adding duplicate keys to `Properties`.

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/ApiResources/ApiResource.cs

@@ -35,7 +35,8 @@ namespace Volo.Abp.IdentityServer.ApiResources
 
         }
 
-        public ApiResource(Guid id, [NotNull] string name, string displayName = null, string description = null) : base(id)
+        public ApiResource(Guid id, [NotNull] string name, string displayName = null, string description = null)
+            : base(id)
         {
             Check.NotNull(name, nameof(name));
 
@@ -122,7 +123,15 @@ namespace Volo.Abp.IdentityServer.ApiResources
 
         public virtual void AddProperty([NotNull] string key, string value)
         {
-            Properties.Add(new ApiResourceProperty(Id, key, value));
+            var property = FindProperty(key);
+            if (property == null)
+            {
+                Properties.Add(new ApiResourceProperty(Id, key, value));
+            }
+            else
+            {
+                property.Value = value;
+            }
         }
 
         public virtual void RemoveAllProperties()

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/ApiScopes/ApiScope.cs

@@ -79,7 +79,15 @@ namespace Volo.Abp.IdentityServer.ApiScopes
 
         public virtual void AddProperty([NotNull] string key, string value)
         {
-            Properties.Add(new ApiScopeProperty(Id, key, value));
+            var property = FindProperty(key);
+            if (property == null)
+            {
+                Properties.Add(new ApiScopeProperty(Id, key, value));
+            }
+            else
+            {
+                property.Value = value;
+            }
         }
 
         public virtual void RemoveAllProperties()

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/Clients/Client.cs

@@ -266,7 +266,15 @@ namespace Volo.Abp.IdentityServer.Clients
 
         public virtual void AddProperty([NotNull] string key, [NotNull] string value)
         {
-            Properties.Add(new ClientProperty(Id, key,value));
+            var property = FindProperty(key);
+            if (property == null)
+            {
+                Properties.Add(new ClientProperty(Id, key, value));
+            }
+            else
+            {
+                property.Value = value;
+            }
         }
 
         public virtual void RemoveAllProperties()

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/Grants/PersistedGrant.cs

@@ -5,14 +5,6 @@ namespace Volo.Abp.IdentityServer.Grants
 {
     public class PersistedGrant : AggregateRoot<Guid>
     {
-        protected PersistedGrant()
-        {
-        }
-
-        public PersistedGrant(Guid id) : base(id)
-        {
-        }
-
         public virtual string Key { get; set; }
 
         public virtual string Type { get; set; }
@@ -32,5 +24,14 @@ namespace Volo.Abp.IdentityServer.Grants
         public virtual DateTime? ConsumedTime { get; set; }
 
         public virtual string Data { get; set; }
+
+        protected PersistedGrant()
+        {
+        }
+
+        public PersistedGrant(Guid id)
+            : base(id)
+        {
+        }
     }
 }

modules/identityserver/src/Volo.Abp.IdentityServer.Domain/Volo/Abp/IdentityServer/IdentityResources/IdentityResource.cs

@@ -56,7 +56,8 @@ namespace Volo.Abp.IdentityServer.IdentityResources
             Properties = new List<IdentityResourceProperty>();
         }
 
-        public IdentityResource(Guid id, IdentityServer4.Models.IdentityResource resource) : base(id)
+        public IdentityResource(Guid id, IdentityServer4.Models.IdentityResource resource)
+            : base(id)
         {
             Name = resource.Name;
             DisplayName = resource.DisplayName;
@@ -91,7 +92,15 @@ namespace Volo.Abp.IdentityServer.IdentityResources
 
         public virtual void AddProperty([NotNull] string key, string value)
         {
-            Properties.Add(new IdentityResourceProperty(Id, key, value));
+            var property = FindProperty(key);
+            if (property == null)
+            {
+                Properties.Add(new IdentityResourceProperty(Id, key, value));
+            }
+            else
+            {
+                property.Value = value;
+            }
         }
 
         public virtual void RemoveAllProperties()