ASP.NET Core MVC中调用Json()时默认使用Newtonsoft.Json返回数据

Newtonsoft.Json

Microsoft.AspNetCore.Mvc.NewtonsoftJson

  public void ConfigureServices(IServiceCollection services)
  {
      services.AddControllers().AddNewtonsoftJson(options =>
            {
                options.SerializerSettings.ContractResolver = new 
      DefaultContractResolver();
            });
  }