public DetailedBox(string st, Student s, IManageStudent l)
 {
     InitializeComponent();
     _link                      = l;
     _student                   = s;
     _mode                      = st;
     boxName.Content            = st + " student";
     comboBox.ItemsSource       = EntityDb.LoadStudies();
     comboBox.DisplayMemberPath = "Name";
     listBox.ItemsSource        = EntityDb.LoadSubjects();
     listBox.DisplayMemberPath  = "Name";
     if (_student != null)
     {
         fBox.Text = _student.FirstName;
         lBox.Text = _student.LastName;
         iBox.Text = _student.IndexNumber;
         foreach (Study study in EntityDb.LoadStudies())
         {
             if (study.IdStudies == _student.IdStudies)
             {
                 comboBox.SelectedItem = study;
             }
         }
         foreach (Student_Subject sb in EntityDb.LoadStudents_Subj())
         {
             if (sb.IdStudent == _student.IdStudent)
             {
                 listBox.SelectedItem = EntityDb.FindSubject(sb.IdSubject);
             }
         }
     }
 }
 public int verifyData()
 {
     if (string.IsNullOrWhiteSpace(lBox.Text) || lBox.Text.Length < 1)
     {
         MessageBox.Show("Wrong input in 1 row!");
         return(0);
     }
     if (string.IsNullOrWhiteSpace(fBox.Text) || fBox.Text.Length < 1)
     {
         MessageBox.Show("Wrong input in 2 row!");
         return(0);
     }
     if (string.IsNullOrWhiteSpace(iBox.Text) || iBox.Text.Length < 2 || !iBox.Text[0].Equals('s') ||
         !int.TryParse(iBox.Text.Substring(1), out int n))
     {
         MessageBox.Show("Wrong index number!(starts with 's' and only numbers after)");
         return(0);
     }
     if (comboBox.SelectedItem == null)
     {
         MessageBox.Show("You should select one study type!");
         return(0);
     }
     if (listBox.SelectedItems == null)
     {
         MessageBox.Show("You should select at least 1 subject!");
         return(0);
     }
     foreach (Study study in EntityDb.LoadStudies())
     {
         if (((Study)comboBox.SelectedItem).IdStudies == study.IdStudies)
         {
             return(study.IdStudies);
         }
     }
     MessageBox.Show("Sth wrong...");
     return(0);
 }