Json options optimization in .NET (#959)

* Performance optimization for ajax communication: Reuse JSONoptions defined for ReadJSON<T> and SerializeToJayrockCompatibleJson<T>.

* Fix mistake in converter added to DeserializationOptions

* Force build.

(cherry picked from commit 37385be)

Author: claudiamurialdo

dotnet/src/dotnetframework/GxClasses/Helpers/JSONHelper.cs

@@ -56,7 +56,6 @@ public override object Read(ref Utf8JsonReader reader, Type typeToConvert, JsonS
 					}
 			}
 		}
-
 		public override void Write(Utf8JsonWriter writer, object value, JsonSerializerOptions options)
 		{
 			throw new NotImplementedException();
@@ -91,12 +90,10 @@ internal override bool IsJsonNull(object jobject)
 		{
 			return jobject == null;
 		}
+		static JsonSerializerOptions DeserializationOptions = new JsonSerializerOptions() { Converters = { new GxJsonConverter() }, AllowTrailingCommas=true };
 		internal override T ReadJSON<T>(string json)
 		{
-			JsonSerializerOptions opts = new JsonSerializerOptions();
-			opts.Converters.Add(new GxJsonConverter());
-			opts.AllowTrailingCommas = true;
-			return JsonSerializer.Deserialize<T>(json, opts);
+			return JsonSerializer.Deserialize<T>(json, DeserializationOptions);
 		}
 		internal override string WriteJSON<T>(T kbObject)
 		{
@@ -106,13 +103,13 @@ internal override string WriteJSON<T>(T kbObject)
 			}
 			return null;
 		}
+		static JsonSerializerOptions JayrockCompatibleOptions = new JsonSerializerOptions() {
+			Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+			Converters = { new CustomDateTimeConverter() },
+			NumberHandling = JsonNumberHandling.AllowNamedFloatingPointLiterals };
 		internal static string SerializeToJayrockCompatibleJson<T>(T value) where T : IJayrockCompatible
 		{
-			JsonSerializerOptions opts = new JsonSerializerOptions();
-			opts.Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping;
-			opts.Converters.Add(new CustomDateTimeConverter());
-			opts.NumberHandling = JsonNumberHandling.AllowNamedFloatingPointLiterals;
-			return JsonSerializer.Serialize(value, opts);
+			return JsonSerializer.Serialize(value, JayrockCompatibleOptions);
 		}
 	}
 #else