WPF/MVVM Quick Start Tutorial

using System.Windows;

namespace Example2
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        #region Members
        SongViewModel _viewModel;
        int _count = 0;
        #endregion

        public MainWindow()
        {
            InitializeComponent();

            //  We have declared the view model instance declaratively in the xaml.
            //  Get the reference to it here, so we can use it in the button click event.
            _viewModel = (SongViewModel)base.DataContext;
        }
        
        private void ButtonUpdateArtist_Click(object sender, RoutedEventArgs e)
        {
            ++_count;
            _viewModel.ArtistName = string.Format("Elvis ({0})", _count);
        }
    }
}