object 类型的传递，传入ServiceKnownType

  /// <summary>
    /// 获取所有的类型
    /// </summary>
    public static class TypeHelper
    {
        public static IEnumerable<Type> GetKnownTypes(ICustomAttributeProvider provider)
        {
            return new[] { typeof(PKGRecord), typeof(List<PKGRecord>), typeof(UploadParam) };
        }
    }

　　在服务接口中定义 [ServiceKnownType("GetKnownTypes", typeof(TypeHelper))] 标签