public static IObservable <T> AsObservable <T>(this INotifyPropertyChanged propertyHolder, Expression <Func <T> > propertyExpression)
{
var property = propertyExpression.Compile();
IConnectableObservable <T> observable = propertyHolder.AsObservablePropertyChanged()
.Where(p => p.EventArgs.PropertyName == PropertyHelper.GetPropertyName(propertyExpression))
.Select(x => property())
.Publish(property());
observable.Connect();
return(observable);
}
