属性扩展

   private bool _Sex;

        public bool Sex
        {
            get { return _Sex; }
            set { _Sex = value; }
        }

        public string SexStr
        {
            get { return _Sex ? "男" : "女"; }
        }


        private DateTime _Birthday;

        public DateTime Birthday
        {
            get { return _Birthday; }
            set { _Birthday = value; }
        }

        public string BirthdayStr
        {
            get { return _Birthday.ToString("yyyy年MM月dd日"); }
        }


        private string _Nation;

        public string Nation
        {
            get { return _Nation; }
            set { _Nation = value; }
        }

        public string NationName
        {
            get
            {
                return new UserNationData().SelectNation(_Nation);
            }
        }

方法

public class UserNationData
    {
        SqlConnection conn;
        SqlCommand cmd;

        public UserNationData()
        {
            conn = new SqlConnection("server=.;database=Date0504;user=sa;pwd=y920106k");
            cmd = conn.CreateCommand();
        }

        public string SelectNation(string nc)
        {
            string s = "无数据";
            cmd.CommandText = "select *from UserNation where NationCode = @a";
            cmd.Parameters.Clear();
            cmd.Parameters.AddWithValue("@a", nc);
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();

            if (dr.HasRows)
            {
                dr.Read();
                s = dr["NationName"].ToString();
            }

            conn.Close();
            return s;
        }

封装