Ellis Web

Declaring Custom Events in User Controls

I am constantly needing to search my code to find the exact syntax for how to do this, so for future reference (for myself and anyone else who finds this useful), to declare and call an event from a custom user control or inherited control:

public class CustomEventArgs : EventArgs {
  public CustomEventArgs(int propValue) {
    _propValue = propValue;
  }

  private int _propValue;
  public int PropValue {
    get { return _propValue; }
  }
}

public delegate void CustomEventHandler(object sender, CustomEventArgs e);
public event CustomEventHandler CustomEvent;

public void Function() {
  // Do Stuff
  if (CustomEvent != null) {
    CustomEventArgs e = new CustomEventArgs(x);
    CustomEvent(this, e);
  }
}

If you don’t need a CustomEventArgs class, just use the built-in EventArgs instead.