public static void Notify <T>(PropertyChangedEventHandler handler, Expression <Func <T> > propertySelector)
{
if (handler == null)
{
return;
}
MemberExpression memberExpression = PropertyChangedExtensions.GetMemberExpression <T>(propertySelector);
if (memberExpression == null)
{
return;
}
object value = ((ConstantExpression)memberExpression.Expression).Value;
handler(value, new PropertyChangedEventArgs(memberExpression.Member.Name));
}
// For - specifically for property changed event args
public static HandlerBase <PropertyChangedEventArgs, PropertyChangedEventHandler> HandleFor
(this HandlerBase <PropertyChangedEventArgs, PropertyChangedEventHandler> handler, Expression <Func <Object> > propertySelector)
{
Guard.ArgumentNotNull(handler, "handler");
Guard.ArgumentNotNull(propertySelector, "propertySelector");
// get the property name
var _propertyName = PropertyChangedExtensions.GetPropertyName(propertySelector);
if (handler.Predicate != null)
{
var _existingPredicate = handler.Predicate;
handler.Predicate = (e) => _existingPredicate(e) &&
(string.Equals(e.EventArgs.PropertyName, _propertyName, StringComparison.InvariantCulture));
}
else
{
handler.Predicate = (e) => string.Equals(e.EventArgs.PropertyName, _propertyName, StringComparison.InvariantCulture);
}
return(handler);
}
public void NotifyPropertyChanged <T>(Expression <Func <T> > propertySelector)
{
PropertyChangedExtensions.Notify(PropertyChanged, propertySelector);
}
