private void BtnAdd_Click(object sender, EventArgs e) { epProgram.Clear(); bool check = SessionsHelper.ControlValidate(txtSessionName, "Lütfen Session İsmini Giriniz.", epProgram); if (check) { if (!SessionsHelper.HaveSessionName(txtSessionName.Text)) { Sessions s = new Sessions(); s.Name = Convert.ToString(txtSessionName.Text).Trim(); s.StartDate = dtpStartDate.Value; s.EndDate = dtpEndDate.Value; SessionsHelper.Add(s); MessageBox.Show("Program Ekleme Başarılı", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Information); FillGrid(); } else { MessageBox.Show("Aynı isimde bir Session zaten ekli!", "Library Management System", MessageBoxButtons.OK, MessageBoxIcon.Error); } } }