BindableBase.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace NonTrivialDataBindingDemoVS
{
    /*
     * An abstract class that implements INotifyPropertyChanged.
     * Subclass BindableBase in your models or view models to make
     * them ready for nontrivial binding.
     */
    public abstract class BindableBase : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            var handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}