public AbsenViewModel(Jadwal data, BeritaAcara model)
 {
     this.Model  = model;
     this.Data   = data;
     this.Dosen  = Helper.Dosen;
     SaveCommand = new Command(SaveAction);
 }
 public AbsenViewModel(Jadwal data)
 {
     Model       = new BeritaAcara();
     this.Data   = data;
     this.Dosen  = Helper.Dosen;
     SaveCommand = new Command(SaveAction);
 }
        /* private async Task completeTaskAsync(Task<BeritaAcara> arg1)
         * {
         *   var ba = await arg1;
         *   if(ba!=null)
         *   {
         *       vm.Model = ba;
         *       jumlah.Nilai = ba.Jumlah;
         *       hadir.Nilai = ba.Hadir;
         *       alpa.Nilai = ba.Alpa;
         *       izin.Nilai = ba.Izin;
         *       sakit.Nilai = ba.Sakit;
         *   }
         * }*/
        public AbsenView(Models.Jadwal data, BeritaAcara ba)
        {
            InitializeComponent();
            this.BindingContext   = vm = new AbsenViewModel(data, ba);
            jumlah.onChangeValue += Jumlah_onChangeValue;
            hadir.onChangeValue  += Hadir_onChangeValue;
            alpa.onChangeValue   += Alpa_onChangeValue;
            sakit.onChangeValue  += Sakit_onChangeValue;
            izin.onChangeValue   += Izin_onChangeValue;
            jumlah.Nilai          = ba.Jumlah;
            hadir.Nilai           = ba.Hadir;
            alpa.Nilai            = ba.Alpa;
            izin.Nilai            = ba.Izin;
            sakit.Nilai           = ba.Sakit;

            /*  var task=  vm.BeritaAcaraStore.GetById(data.JadwalId, DateTime.Now);
             * task.ContinueWith(completeTaskAsync);*/
        }