Can Attributes be used for automatic change notification/logging?

Is there a way to do this:

class Example {
    [ChangeNotification]
    private int field;
}

Such that changing the value of "field" would automatically get logged, g开发者_如何学JAVAenerate an event, etc?

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No, attributes are type specific, not instance specific.

But you can implement INotifyPropertyChanged on all you objects and have some class listen to all the events and do the logging.

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At first view, I would better recommend that you implement the INotifyPropertyChanged interface, as an Attribute is type specific.

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You can do something similar (at least to a property, but not to a field) via Aspect oriented programming. However, this requires the use of a program like PostSharp, which actually rewrites the code inline based on the attribute.

Typically, this is used to implement INotifyPropertyChanged on a property. However, there are rewrite rules for logging and other features available.

This won't work for a field, however. It does work for a property, since the rewriter can add code to the property set method, but a field is handled directly by the CLR.

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yes it's possible with postsharp using OnFieldAccessAspect http://www.sharpcrafters.com/forum/Topic2244-4-1.aspx