void Program_Preparer()
 {
     try
     {
         Person person  = JsonConvert.DeserializeObject <Person>(Settings.GeneralSettings);
         string dersids = $"select ders_id from derskayit where student_id = '{person.Id}'";
         Dictionary <string, List <string> > ders_ids = HelperFunctionss.Sqlreaderexecuter(dersids);
         foreach (string id in ders_ids["ders_id"])
         {
             string ders = $"select DersGünü,DersAdi,hoca_id,cast(date2 as time(0))[time] from Dersler where Ders_ID = '{id}'";
             Dictionary <string, List <string> > dersler = HelperFunctionss.Sqlreaderexecuter(ders);
             string hocaisim = $"select isim from Hocalar where Hoca_id = '{dersler["hoca_id"][0]}'";
             hocaisim = HelperFunctionss.SqlExecuter(hocaisim, 1);
             Label label = new Label
             {
                 Text = dersler["DersAdi"][0] + "\n" + hocaisim,
             };
             label.FontSize = Device.GetNamedSize(NamedSize.Micro, label);
             string lname = dersler["time"][0].Replace(":", "");
             lname = "l" + lname;
             int row = Grid.GetRow(Grid.FindByName <Label>(lname));
             int col = Grid.GetColumn(Grid.FindByName <Label>(dersler["DersGünü"][0]));
             Grid.Children.Add(label, col, row);
         }
     }
     catch (Exception exp)
     {
         DisplayAlert("", exp.ToString(), "ok");
     }
 }
        void Button7_Clicked(object sender, EventArgs e)
        {
            Button_invisible();
            if (Brans.SelectedIndex != -1 && Hocalar.SelectedIndex != -1 && Gun.SelectedIndex != -1)
            {
                try
                {
                    string hocaid = $"select Hoca_id from Hocalar where isim = '{Hocalar.SelectedItem.ToString()}'";
                    hocaid = HelperFunctionss.SqlExecuter(hocaid, 1);
                    string comm = $@"SELECT cast(date2 as time(0))[date2] from Dersler 
                    WHERE DersAdi = '{Brans.SelectedItem.ToString()}' 
                    and hoca_id = '{hocaid}' 
                    and DersGünü = '{Gun.SelectedItem.ToString()}' and enrolled != quota";
                    Dictionary <string, List <string> > table = HelperFunctionss.Sqlreaderexecuter(comm);
                    Person person1 = JsonConvert.DeserializeObject <Person>(Settings.GeneralSettings);
                    comm = $@"SELECT cast(Dersler.date2 as time(0))[date2]
                              FROM Dersler
                              INNER JOIN derskayit ON Dersler.Ders_ID = derskayit.ders_id
                              where derskayit.student_id = '{person1.Id}' 
                              and DersGünü = '{Gun.SelectedItem.ToString()}';";
                    Dictionary <string, List <string> > kayitlitimes = HelperFunctionss.Sqlreaderexecuter(comm);

                    DersGunu.Text = Gun.SelectedItem.ToString();
                    foreach (string row in table["date2"])
                    {
                        string bname = "b" + row.Replace(":", "");
                        string lname = "l" + row.Replace(":", "");
                        string rname = "r" + row.Replace(":", "");
                        if (!(kayitlitimes["date2"].Contains(row)))
                        {
                            try
                            {
                                Grid.IsVisible = true;
                                Grid.FindByName <Button>(bname).IsVisible     = true;
                                Grid.FindByName <Label>(lname).IsVisible      = true;
                                Grid.FindByName <RowDefinition>(rname).Height = GridLength.Star;
                            }
                            catch
                            {
                            }
                        }
                    }
                    if (Grid.IsVisible == false)
                    {
                        DisplayAlert("Uyarı", "Kayıt olabileceğiniz Ders bulunmamaktır lütfen Ders Programınızı Kontrol Ediniz", "Tamam");
                    }
                }

                catch (Exception exx)
                {
                    DisplayAlert("alert", exx.ToString(), "ok");
                }
            }
            else
            {
                DisplayAlert("Uyarı", "Lutfen butun seçenekleri eksiksiz seçiniz", "OK");
            }
        }
 void Hocalar_SelectedIndexChanged(object sender, EventArgs e)
 {
     if (Hocalar.SelectedIndex != -1)
     {
         string hocaid = $"select Hoca_id from Hocalar where isim = '{Hocalar.SelectedItem.ToString()}'";
         hocaid = HelperFunctionss.SqlExecuter(hocaid, 1);
         string comm = $@"SELECT DersGünü from Dersler 
         WHERE DersAdi = '{Brans.SelectedItem.ToString()}' 
         and hoca_id = '{hocaid}' and enrolled != quota";
         Dictionary <string, List <string> > names = HelperFunctionss.Sqlreaderexecuter(comm);
         HelperFunctionss.Pickeradjuster(Gun, names, "DersGünü");
         Grid.IsVisible = false;
     }
 }
        void Button8_Clicked(object sender, System.EventArgs e)
        {
            try
            {
                Button   btn   = (Button)sender;
                string[] hours = new string[] { "10:50:00", "11:10:00", "13:00:00", "13:30:00", "14:00:00", "14:30:00", "17:00:00", "17:30:00" };

                foreach (string bhour in hours)
                {
                    string bname = "b" + bhour.Replace(":", "");
                    if (btn == Grid.FindByName <Button>(bname))
                    {
                        string hocaid = $"select Hoca_id from Hocalar where isim = '{Hocalar.SelectedItem.ToString()}'";
                        hocaid = HelperFunctionss.SqlExecuter(hocaid, 1);
                        string comm    = $@"select Ders_ID from Dersler where DersAdi = '{Brans.SelectedItem.ToString()}'
                                        and hoca_id = '{hocaid}'
                                        and DersGünü = '{Gun.SelectedItem.ToString()}'
                                        and cast(date2 as time(0)) = '{bhour}'";
                        string dersid  = HelperFunctionss.SqlExecuter(comm, 1);
                        Person person1 = JsonConvert.DeserializeObject <Person>(Settings.GeneralSettings);
                        if (dersid != "null")
                        {
                            comm = $@"insert into derskayit(student_id,ders_id) values('{person1.Id}','{dersid}')
                                      update Dersler set enrolled = enrolled + 1 where Ders_ID = '{dersid}'";
                            string ret = HelperFunctionss.SqlExecuter(comm, 0);
                            if (ret == "null")
                            {
                                DisplayAlert("alert", "Zaten bu derse kayıt olmuşsunuz!", "ok");
                                return;
                            }
                            else
                            {
                                DisplayAlert("alert", "Ders Kaydı Başarılı!", "ok");
                            }
                        }
                        btn.IsVisible = false;
                        break;
                    }
                }
            }
            catch (Exception exaa)
            {
                DisplayAlert("", exaa.Message + exaa.ToString(), "");
            }
        }
 void Ders_Olustur(object sender, System.EventArgs e)
 {
     if (Sinif.SelectedIndex != -1 && Hocalar.SelectedIndex != -1 && Brans.SelectedIndex != -1 && Tarih.Date.ToString() != "" && Saat.SelectedIndex != -1)
     {
         string Gun    = Hangi_gun();
         string tarih  = Tarih.Date.ToString("yyyy - MM - dd ");
         string hocaid = $"select Hoca_id from Hocalar where isim = '{Hocalar.SelectedItem.ToString()}'";
         hocaid = HelperFunctionss.SqlExecuter(hocaid, 2);
         string yenidersekle = $"insert into Dersler (Sınıf,DersGünü,DersAdi,date2,hoca_id,quota,enrolled)" +
                               $"values('{Sinif.SelectedItem.ToString()}','{Gun}','{Brans.SelectedItem.ToString()}','{tarih + Saat.SelectedItem.ToString()}','{hocaid}','1','0')";
         if (HelperFunctionss.SqlExecuter(yenidersekle, 0) == "null")
         {
             DisplayAlert("Hata!", "Lütfen ders programını kontrol ediniz", "Tamam");
         }
     }
     else
     {
         DisplayAlert("Uyarı", "Lütfen bütün seçenekleri seçtiğinizden emin olun.", "Tamam");
     }
 }