public class Base : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        var handler = this.PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    protected void SetProperty<T>(ref T field, T value, [CallerMemberName] string propertyName = "")
    {
        if (!EqualityComparer<T>.Default.Equals(field, value))
        {
            field = value;
            OnPropertyChanged(propertyName);
        }
    }
}


// Использование.

public MyClass : Base
{
    private string _myField;
    public string MyProperty
    {
        get { return _myField; }
        set { this.SetProperty<string>(ref _myField, value); }
    }
}

class Model
{
    public int A { get; set; }
}

class ViewModel
{
    Model _model;
    
    public int A
    {
        get { return _model.A; }
        set { SetProperty(ref _model.A, value); }
    }
}

        set
        {
            var a = _model.A;
            SetProperty(ref a, value);
            _model.A = a;
        }

SetProperty (string proprtyName)
{
    if (OnPropertyCanged != null)
    {
         OnPropertyCanged (new ProprtyChangedEvenArgument(proprtyName));
    }
}

public int A
{
    set { SetProperty(v => _model.A = v, value); }
}

protected void SetProperty<T>(Expression<Action<T>> e, T value, [CallerMemberName] string propertyName = "")
{
    var action = e.Compile();
    action.Invoke(value);
}

            if (!EqualityComparer<T>.Default.Equals(field, value))
            {
                field = value;
            }

 public ReceiptLine SelectedReceiptLine
        {
            get { return _selectedGiftReceiptLine; }
            set
            {
                if (_selectedReceiptLine == value) return;
                _selectedReceiptLine = value;
                NotifyPropertyChanged("SelectedReceiptLine");
            }
        }

 protected void NotifyPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

 protected void NotifyPropertyChanged(string propertyName)
        {
            var handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }

protected void SetProperty<T>(Func<T> getter, Action<T> setter, T newValue, [CallerMemberName] string propertyName = "")
{
    var oldValue = getter();

    if (!EqualityComparer<T>.Default.Equals(oldValue, newValue))
    {
        setter(newValue);
        OnPropertyChanged(propertyName);
    }
}

set { SetProperty(() => _model.A, newValue => _model.A = newValue, value); }

class MyEntity
{
    public virtual int Value { get; set; }
}

// Там внутри через Emit замутить потомка указанного класса, перекрыть виртуальное
// свойство и сгенерировать в него что хочешь.
var obj = NotificationFactory.Create<MyEntity>();