private static PropertyChangedEventArgs CurrentItemChangedEventArgs = new PropertyChangedEventArgs("CurrentItem");
private static PropertyChangedEventArgs CurrentPositionChangedEventArgs = new PropertyChangedEventArgs("CurrentPosition");
private static PropertyChangedEventArgs IsCurrentBeforeFirstChangedEventArgs = new PropertyChangedEventArgs("IsCurrentBeforeFirst");
 
...
 
this.PropertyChanged(this, CurrentItemChangedEventArgs);
this.PropertyChanged(this, CurrentPositionChangedEventArgs);
this.PropertyChanged(this, IsCurrentBeforeFirstChangedEventArgs);