private void Form1_Load(object sender, EventArgs e) { TipNesneUret musteriUret = new TipNesneUret(); Musteri musteri = musteriUret.MusteriNesneUret("12345678901"); Numarator numarator = Numarator.Instance; numarator.Musteri = musteri; MessageBox.Show(musteri.NumaraAl().ToString()); }