From MSDN:
The INotifyPropertyChanged interface is used to notify clients, typically binding clients, that a property value has changed.
Step 1 create an abstract class that encapsulates all the functionality we need.
See below for a class diagram:
Step 2 create the handler:
NotifyPropertyChangedHandler which inherits from ICallHandler
public IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext) {
IMethodReturn result = getNext()(input, getNext);
if (!input.MethodBase.Name.StartsWith("set_")) return result;
//Remov the set_ to get the property's name
var propertyName = input.MethodBase.Name.Remove(0, 4);
//invoke the modified property
//maybe we should check if the target is indeed o BindableOjectBase ;)
BindableObjectBase target = (BindableObjectBase)input.Target;
((IBindableObject)target).Modified(propertyName);
return result;
}
Step 3: Create the attribute
Create a NotifyPropertyChangedAttribute class which inherits from HandlerAttribute
create a default constructor:
public NotifyPropertyChangedAttribute() {
_CallHandler = new NotifyPropertyChangedHandler();
}
override the folowing method
public override ICallHandler CreateHandler(IUnityContainer container) {
return _CallHandler;
}
Step 4: Setting up the UnityContainer:
UnityContainer_Container = new UnityContainer();
//Registring interception extension
_Container.AddNewExtension
_Container.RegisterInstance
_Container.Configure
var object container.Resolve
the last step took a little time to get it working the way I wanted since DI usually works by injecting interface implementations but this was not what I wanted to do. Since interfaces define behaviour and properties have nothing to do with behaviour but with state.
I will post the full source code later
