How To Raise Property Changed events on a Dependency Property?

Question

I have a control with two properties. One is a DependencyProperty, the other is an \"alias\" to the first one. How do I raise the PropertyChanged

Answer 1

1. Implement INotifyPropertyChanged in your class.

2. Specify a callback in the property metadata when you register the dependency property.

3. In the callback, raise the PropertyChanged event.

Adding the callback:

public static DependencyProperty FirstProperty = DependencyProperty.Register(
  "First", 
  typeof(string), 
  typeof(MyType),
  new FrameworkPropertyMetadata(
     false, 
     new PropertyChangedCallback(OnFirstPropertyChanged)));

Raising PropertyChanged in the callback:

private static void OnFirstPropertyChanged(
   DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
   PropertyChangedEventHandler h = PropertyChanged;
   if (h != null)
   {
      h(sender, new PropertyChangedEventArgs("Second"));
   }
}