Get data with TextBox

I delve into WPF and MVVM. From the beginning I wrote this:

private void Button_Click(object sender, RoutedEventArgs e) { if(String.IsNullOrEmpty(txtAccountLogin.Text) || String.IsNullOrEmpty(txtAccountPassword.Text)) { MessageBox.Show("Все поля должны быть заполнены!", "Ошибка!", MessageBoxButton.OK, MessageBoxImage.Error); } else { using (Cursor = Cursors.Wait) { using (AccountContext ac = new AccountContext()) { Account account = new Account(); account.login = txtAccountLogin.Text; account.password = txtAccountPassword.Text; ac.Accounts.Add(account); ac.SaveChanges(); MessageBox.Show("Аккаунт " + account.login + " добавлен.", "Сообщение", MessageBoxButton.OK, MessageBoxImage.Information); txtAccountLogin.Text = ""; txtAccountPassword.Text = ""; } } } } 

But then I realized that the code should not know anything about the interface. The question is, I need to create a "account" model, inherit it from INotifyPropertyChanged to make event changes fields. Then you need to make an AccountViewModel and in it and beyond I do not understand what's next. By clicking the button, what should I contact to get the text from the controls? Do I understand correctly that because of the change event, the binding will also change the state of the property? Here is my example of how I did it with the DataGrid :

 class Message: INotifyPropertyChanged { public string author { get; set; } public string message { get; set; } public string bulletinText { get; set; } public int id { get; set; } public event PropertyChangedEventHandler PropertyChanged; } class MessageViewModel: INotifyPropertyChanged { private Message Message { get; set; } public ObservableCollection<Message> Messages { get; set; } public MessageViewModel() { Messages = new ObservableCollection<Message> { new Message{ author = "Федор Иванович", bulletinText = "Привет, как дела?", message = "Продам собаку", id = 154 }, new Message{ author = "Меткий снайпер", bulletinText = "Сообщите номер накладной?", message = "Доставка овощей", id = 255} }; } public event PropertyChangedEventHandler PropertyChanged; public void OnPropertyChanged([CallerMemberName]string prop = "") { if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(prop)); } } public Main() { InitializeComponent(); DataContext = new MessageViewModel(); } 

XAML:

 <DataGrid CanUserAddRows="False" ItemsSource="{Binding Messages}" DockPanel.Dock="Top" AutoGenerateColumns="False" HorizontalAlignment="Stretch" VerticalScrollBarVisibility="Auto" VerticalAlignment="Stretch" Margin="5,0,0,0" MouseDoubleClick="DataGrid_MouseDoubleClick"> <DataGrid.Columns> <DataGridTextColumn Header="От кого" Binding="{Binding Path=author}" Width="*" IsReadOnly="True" /> <DataGridTextColumn Header="Сообщение" Binding="{Binding Path=message}" Width="*" IsReadOnly="True" /> <DataGridTextColumn Header="Превью объявления" Binding="{Binding Path=bulletinText}" Width="*" IsReadOnly="True" /> </DataGrid.Columns> </DataGrid> 

This is how I capture the click event:

 private void DataGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e) { DataGrid grid = (DataGrid)sender; int id = (grid.SelectedItem as Message).id; MessageBox.Show(id.ToString()); } 

How to do in the first part of my question?