oap_labs/WpfApp1/model/Class4.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;

namespace WpfApp1.model
{
    [DataContract]
    public class Client
    {
        [DataMember]
        public string Name { get; set; }
        [DataMember]
        public int Age { get; set; }
        [DataMember]
        public int Price { get; set; }
        [DataMember]
        public string Place { get; set; }
        [DataMember]
        public string Category { get; set; }
        [DataMember]
        public bool IsActive { get; set; }

        [DataMember(Name = "DateFlight")]
        private string? stringDate { get; set; }

        [IgnoreDataMember]
        public DateTime? DateFlight
        {
            get
            {
                return stringDate == null ? null : DateTime.Parse(stringDate);
            }
            set
            {
                stringDate = value.ToString();
            }
        }
    }
}