public void Delete()
 {
     if (DeleteYesNoHelper.DeleteYesNoMessageBox("Искате ли да изтриете този елемент ?", "Изтриване"))
     {
         DbContext.PROPERTYTYPES.Remove(DbContext.PROPERTYTYPES.Where(p => p.ID == SelectedPropertyType.ID).FirstOrDefault());
         DbContext.SaveChanges();
         PropertyTypesList.Remove(SelectedPropertyType);
         IsDirty = true;
     }
 }
        public PropertyTypesViewModel()
        {
            DeletePropType = new RelayCommand(Delete, () => { return(PropertyTypesList.Contains(SelectedPropertyType)); });

            //SelectedPropertyType = new PropertyTypeViewModel();
            AddedPropertyType = new PropertyTypeViewModel();
            PropertyTypesList = new ObservableCollection <PropertyTypeViewModel>();
            ObservableCollection <PROPERTYTYPES> ptl = new ObservableCollection <PROPERTYTYPES>(DbContext.PROPERTYTYPES.ToList());

            foreach (var pT in ptl)
            {
                PropertyTypesList.Add(new PropertyTypeViewModel(pT));
            }
            IsDirty = false;
        }