title: ObservableCollection and Item PropertyChanged
body: <p>I've seen lots of talk about this question but maybe I'm just too much of a newbie to get it. If I have an observable collection that is a collection of "PersonNames" as in the msdn example (<a href="http://msdn.microsoft.com/en-us/library/ms748365.aspx" rel="noreferrer">http: //msdn.microsoft.com/en-us/library/ms748365.aspx</a>), I get updates to my View if a <code>PersonName</code> is added or removed, etc. I want to get an update to my View when I change a property in the <code>PersonName</code> as well. Like if I change the first name. I can implement <code>OnPropertyChanged</code> for each property and have this class derive from <code>INotifyPropertyChanged</code> and that seems to get called as expected. </p>
  
  <p>My question is, <em>how does the View get the updated data from the <code>ObservableCollection</code> as the property changed does not cause any event for the <code>ObservableCollection</code>?</em> </p>
  
  <p>This is probably something really simple but why I can't seem to find an example surprises me. Can anyone shed any light on this for me or have any pointers to examples I would greatly appreciate it. We have this scenario in multiple places in our current WPF app and are struggling with figuring it out.</p>
  
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  <p>"Generally, the code responsible for displaying the data adds a <code>PropertyChanged</code> event handler to each object currently displayed onscreen."</p>
  
  <p>Could someone please give me an example of what this means? My View binds to my <code>ViewModel</code> which has a <code>ObservableCollection</code>. This collection is made up of a <code>RowViewModel</code> which has properties that support the <code>PropertiesChanged</code> event. But I can't figure out how to make the collection update itself so my view will be updated.</p>