private void comboCourse_SelectedIndexChanged(object sender, EventArgs e) { btnStopAttendance.Visible = false; lblCourse.Visible = false; lblRegistered.Visible = false; btnTakeAttendance.Enabled = false; if (comboCourse.SelectedIndex > 0) { _courseId = comboCourse.SelectedValue.ToString(); _studentFingers = _repo.GetFingersOfCourseStudents(_courseId); if (_studentFingers == null) { Base.ShowError("", "There is no active semester. You cannot take attendance"); return; } if (_studentFingers.Count == 0) { Base.ShowError("", "There is no registered students with fingerprints enrolled. You cannot take attendance"); return; } btnTakeAttendance.Enabled = true; lblCourse.Text = comboCourse.SelectedText; lblCourse.Visible = true; lblRegistered.Text = "Registered Students (with Fingerprints enrolled): " + _studentFingers.Select(x => x.StudentId).Distinct().Count().ToString(); lblRegistered.Visible = true; comboScanner.Items.Clear(); comboScanner.Items.Add("Digital Persona Scanner"); comboScanner.SelectedIndex = 0; comboScanner.Enabled = true; LoadTodayAttendanceForCourse(); } }