C＃中的子女父母财产变更

Question

I have a property in a class (eg ParentClass ) in C# that is binding with ObservableCollection of another class Type (eg ChildClass ). My question is how to change the value of ChildClass property by using the ParentClass property such that RaisePropertyChanged("ParentProperty") should get triggered?

I use this coding:

foreach (var pIn in ParentProperty.Where(ms => ms.Name == onNameUpdateObj.Name && ms.UnRead == true))
{
    if (pIn != null)
    {
         pIn.UnRead = false;
    }
}

ParentProperty is the property binding with ObservableCollection<ChildClass> and ChildClass contains the property UnRead . When I change the value of UnRead RaisePropertyChanged("ParentProperty") returns null . I want RaisePropertyChanged("ParentProperty") to be triggered whenever I change the property value of pIn.UnRead .

Answer 1

ObservableCollection<T> does not provide notifications for when one or more properties of the collection it maintains change, it only provides notifications for when items get added, removed, or when the whole list is refreshed .

If you want to know when a property in your collection changes, you need to implement a notification for that yourself. Such a mechanism can be implemented with the aid of INotifyPropertyChanged and/or EventHandler .