IObservable<T> and INotifyPropertyChanged - is there a connection

wpf data-binding binding inotifypropertychanged system.reactive
AwkwardCoder picture AwkwardCoder · Jan 29, 2010 · Viewed 7.3k times · Source

I understand the IObservable<T> & IObserver<T> are implementations of the observer pattern and can be used in similar circumstances to .Net events.

I was wondering if there is any relationship to INotifyPropertyChanged?

I currently use INotifyPropertyChanged for data binding in winforms & WPF applications and was wondering if I'll be able to use IObservable in UI data binding scenarios?

Cheers

AWC

Answer

micahtan picture micahtan · Feb 9, 2010

From what I can gather, there is no relationship. Observers/.NET eventing are two ways of achieving the Observer/Notification style behavior.

Microsoft's answer has been to build on top of the .NET eventing pattern, not deprecate it in favor of manually registered Observer objects.

One of my biggest peeves with events is the inability to clear the delegate chain on demand, which leads to quite a few managed-memory leak scenarios. To this end, Microsoft introduced the concept of weak events, that is, to address the issue of mismatched timelines for Observables/Observers.

You can read more about the WeakEvent pattern here.

Josh Smith has released an implmentation of the WeakEventManager for INotifyPropertyChanged here. This provides a safer (from a memory-standpoint) way of hooking up objects which change properties, and their Observers.

Related questions

How to bind multiple values to a single WPF TextBlock?

I'm currently using the TextBlock below to bind the value of a property named Name: <TextBlock Text="{Binding Name}" /> Now, I want to bind another property named ID to the same TextBlock. Is it possible to bind two …

Read More
WPF Bind to itself

I've got a WPF Window, and somewhere there is a ListView where I bind a List<string> to. Now somewhere in my ListView there is a TextBox and the Content property is set to {Binding}. But this is …

Read More
ComboBox.SelectedValue not updating from binding source

Here's my binding source object: Public Class MyListObject Private _mylist As New ObservableCollection(Of String) Private _selectedName As String Public Sub New(ByVal nameList As List(Of String), ByVal defaultName As String) For Each name In nameList _mylist.Add(name) …

Read More