Question

Is it possible for a User control to receive an update whenever a user control changes value? I have a form with a save button and I want to activate it as soon as a value changes.

Currently I am ding this using my View but I have to add a call to every property when it changes. This is OK but for edit boxes it means the user has to tab away before the save button becomes active.

Answer 1

If you bind your view to a view model then you can have a flag IsDirty inside view model which will be set every time you fire PropertyChanged event

    protected void FirePropertyChanged(string propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        _isDirty = true;
        if(handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

Then bind your button with IsDirty