抽象类的布尔值不会改变

Question

我写了一个MySQL连接和查询类，他们都检查了Baglanti Class的Connected状态，但是这里没有更新的值是我的类。 这是Baglanti Class

abstract class Baglanti
{
    protected MySqlConnection connDB
    { get; set; }
    public bool Connected { get; set; }
}

连接类

class DB : Baglanti
{
    private LogStream Writer { get; set; }
    public void Baglan()
    {
        Writer = new LogStream();
        var uid = "*****";
        var pwd = "*****";
        string connectionString;
        connectionString = "SERVER=localhost;DATABASE=****;" + "UID=" + uid + ";" + "PASSWORD=" + pwd + ";";
        connDB = new MySqlConnection(connectionString);
        if (OpenConnection() == true)
        {
            base.Connected = true;
            Writer.Info_Log("Veritabanı Bağlantısı Kuruldu.");
        }
        else { base.Connected = false; }
    }
    private bool OpenConnection()
    {
        try
        {
            connDB.Open();
            base.Connected = true;
            return true;
        }
        catch (MySqlException ex)
        {
            switch (ex.Number)
            {
                case 0:
                    Writer.Hata_Log("Veritabanına bağlantı kurulamadı.");
                    break;

                case 1045:
                    Writer.Hata_Log("Veritabanı Kullanıcı-Şifre Hatası.");
                    break;
            }
            return false;
        }
    }
}

这是查询类

 class Islem : Baglanti
{
    private LogStream Writer { get; set; }
    public Islem()
    {
        Writer = new LogStream();
    }
    public bool GirisKontrol(string id,string pw)
    {
        if(base.Connected)
        {
            MySqlCommand cmd = new MySqlCommand("SELECT count(*) FROM *** WHERE (**** = @user AND **** = @sifre)", connDB);
            cmd.Parameters.AddWithValue("@user", id);
            cmd.Parameters.AddWithValue("@sifre", pw);
            int valid = int.Parse(cmd.ExecuteScalar().ToString());
            if (valid > 0)
            { return true; }
            else { return false; }
        } else { Writer.Hata_Log("Veritabanı Bağlantısı Yok."); return false; }

    }
}

我的主线程执行Baglan（）void然后当我想从Islem执行GirisKontrol时，它总是返回false，而DB Connection不存在。我从公共布尔检查了在Baglanti Class连接