Question

I have this small problem. I want to capture every time a property is changed.

This property is wrapped inside another user control:

var color = (CustomWPFColorPicker.ColorPickerControlView) elementHost1.Child;
color.CurrentColor <--This property.

How can I detect when the CurrentColor property has changed?

Answer 1

Implement INotifyPropertyChanged on your custom control and raise the PropertyChanged event when the given properties change.

The consumer can then register for the PropertyChanged event and check the property which raised the event to see if it is the property they care about.

public class MyControl : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }

    private Color _color = null;
    public Color CurrentColor
    {
        get
        {
            return _color;
        }

        set
        {
            _color = value;
            NotifyPropertyChanged("CurrentColor");
        }
    }
}

Then the consumer can register for the event and check the property as needed…

   MyControl control = new MyControl();
   control.PropertyChanged += OnPropertyChanged;

   void OnPropertyChanged(object sender, PropertyChangedEventArgs e)
   {
      if (e.PropertyName == "CurrentColor")
      {
          //do stuff...
      }
   }