private void Edit_Button_Click(object sender, RoutedEventArgs e) { if (courseNumberTB.Text == "" || courseNumberTB.Text == "" || courseMeetingTimeTB.Text == "" || datepicker.SelectedDate == null) { MessageBox.Show("Please enter all information."); } else { FileReadWrite file = new FileReadWrite(); Course EditCourse = new Course(Convert.ToInt32(courseNumberTB.Text), courseNameTb.Text, courseMeetingTimeTB.Text, (DateTime)datepicker.SelectedDate); student.CourseList[index] = EditCourse; file.EditCourseToFile(student, oldCourse, EditCourse); ViewCourses vc = new ViewCourses(student); this.Close(); vc.Show(); } }