How to raise an event when an Bitmap property is changed?

Question

I have an bitmap and an property like this :

   private Bitmap host_Bitmap;
   private Bitmap Host_Bitmap {get;set;}

How can I create an event when the host_Bitmap change?

Answer 1

If you want to take the simple route for one property, you add an event, and in the set you invoke it:

public event EventHandler BitmapChanged;

private Bitmap _hostBitmap;
public Bitmap HostBitmap { get => _hostBitmap;
  set{
    _hostBitmap = value;
    BitmapChanged?.Invoke(this, EventArgs.Empty);
  }
}

If you want to pass more info about the event you can provide a modified EventArgs subclass and declare the BitmapChanged property type to be EventHandler<YourEventArgsSubclass>

If you have a lot of properties to associate with events, look at implementing INotifyPropertyChanged