public static void OnChanging(IPropertyOwner owner, params string[] propertyNames)
{
if (activeNotifiers.TryGetValue(owner, out PropertyChangeNotifier pcn))
{
string[] newChangingProperties = propertyNames.Except(pcn.changingProperties).ToArray();
if (newChangingProperties.Length > 0)
{
pcn.changingProperties.UnionWith(newChangingProperties);
owner.NotifyChanging(newChangingProperties);
}
}
else
{
owner.NotifyChanging(propertyNames);
}
}