AddNewtonsoftJson を指定している場合は以下にすること!
services.AddMvc(c => { }) .AddNewtonsoftJson( options => { options.SerializerSettings.NullValueHandling = NullValueHandling.Ignore; options.SerializerSettings.ContractResolver = new DefaultContractResolver(); options.SerializerSettings.StringEscapeHandling = StringEscapeHandling.EscapeHtml; options.SerializerSettings.Error = (object sender, ErrorEventArgs args) => { // handle error }; } );
Thanks!