Здравствуйте.
Изучая MVVM и EntityFramework возник вопрос как работать с двумя и более таблицами. Поиск в интернете выдает статьи где довольно понятно разбирается работа с одной таблицей.
Есть тестовый проект в в виде телефонного справочника. Информация об абонентах выводится/редактируется. Подскажите как наладить работу с (второй таблицей) телефонными номерами.
| C# |
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| public class Abonent : INotifyPropertyChanged
{
public int Id { get; set; }
private string fio;
private string address;
public string Fio
{
get { return fio; }
set
{
fio = value;
OnPropertyChanged("Fio");
}
}
public string Address
{
get { return address; }
set
{
address = value;
OnPropertyChanged("Address");
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName]string prop = "")
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
} |
|
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| public class ApplicationViewModel : INotifyPropertyChanged
{
ApplicationContext db;
RelayCommand addCommand;
RelayCommand editCommand;
RelayCommand deleteCommand;
IEnumerable<Abonent> abonents;
public IEnumerable<Abonent> Abonents
{
get { return abonents; }
set
{
abonents = value;
OnPropertyChanged("Abonents");
}
}
public ApplicationViewModel()
{
db = new ApplicationContext();
db.Abonents.Load();
Abonents = db.Abonents.Local.ToBindingList();
}
// команда добавления
public RelayCommand AddCommand
{
get
{
return addCommand ??
(addCommand = new RelayCommand((o) =>
{
AbonentWindow abonentWindow = new AbonentWindow(new Abonent());
if (abonentWindow.ShowDialog() == true)
{
Abonent abonent = abonentWindow.Abonent;
db.Abonents.Add(abonent);
db.SaveChanges();
}
}));
}
}
// команда редактирования
public RelayCommand EditCommand
{
get
{
return editCommand ??
(editCommand = new RelayCommand((selectedItem) =>
{
if (selectedItem == null) return;
// получаем выделенный объект
Abonent abonent = selectedItem as Abonent;
Abonent vm = new Abonent()
{
Id = abonent.Id,
Fio = abonent.Fio,
Address = abonent.Address
};
AbonentWindow abonentWindow = new AbonentWindow(vm);
if (abonentWindow.ShowDialog() == true)
{
// получаем измененный объект
abonent = db.Abonents.Find(abonentWindow.Abonent.Id);
if (abonent != null)
{
abonent.Fio = abonentWindow.Abonent.Fio;
abonent.Address = abonentWindow.Abonent.Address;
db.Entry(abonent).State = EntityState.Modified;
db.SaveChanges();
}
}
}));
}
}
// команда удаления
public RelayCommand DeleteCommand
{
get
{
return deleteCommand ??
(deleteCommand = new RelayCommand((selectedItem) =>
{
if (selectedItem == null) return;
// получаем выделенный объект
Abonent abonent = selectedItem as Abonent;
db.Abonents.Remove(abonent);
db.SaveChanges();
}));
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName]string prop = "")
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
} |
|
| XML |
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| <Window x:Class="TSprv.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:TSprv"
mc:Ignorable="d"
Title="MainWindow" Height="300" Width="425">
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="50" />
</Grid.RowDefinitions>
<ListBox x:Name="abonentsList" ItemsSource="{Binding Abonents}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Fio}" FontSize="16" />
<TextBlock Text="{Binding Address}" FontSize="12" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<StackPanel Grid.Row="1" Orientation="Horizontal" HorizontalAlignment="Center">
<Button Content="Добавить" Margin="10" Command="{Binding AddCommand}" />
<Button Content="Изменить" Margin="10" Command="{Binding EditCommand}"
CommandParameter="{Binding ElementName=abonentsList, Path=SelectedItem}" />
<Button Content="Удалить" Margin="10" Command="{Binding DeleteCommand}"
CommandParameter="{Binding ElementName=abonentsList, Path=SelectedItem}" />
</StackPanel>
</Grid>
</Window> |
|
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| public class RelayCommand : ICommand
{
private Action<object> execute;
private Func<object, bool> canExecute;
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public RelayCommand(Action<object> execute, Func<object, bool> canExecute = null)
{
this.execute = execute;
this.canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
return this.canExecute == null || this.canExecute(parameter);
}
public void Execute(object parameter)
{
this.execute(parameter);
}
} |
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| public class ApplicationContext : DbContext
{
public ApplicationContext() : base("DefaultConnection")
{
}
public DbSet<Abonent> Abonents { get; set; }
} |
|
(
Сообщение от mansters
