CompositeWPF/Prism EventAggregation Exception

Just a small reminded for myself. When you are using Publish/Subscribe EventAggregation mechanism provided by PRISM along with Unity to resolve types. It’s important to specify the Action method on subscribe to be public. Example: TextChangedEvent evt = eventAggregator.GetEvent<TextChangedEvent>(); evt.Subscribe(OnSubscibeForNewText); /// /// public void OnSubscibeForNewText(string payload) If it’s not public, Unity will have issues resolving the type and you’ll see an exception as shown below Attempt by method ‘Microsoft.Practices.Composite.Events.DelegateReference.TryGetDelegate()’ to access method ‘ModuleA.ViewModel.ModuleAView2VM.OnSubscibeForNewText(System.String)’ failed.