Question

I want my C# code to call an event whenever a value is assigned to my object.

How exactly would I need to go about that?

class MyClass {

  ManualResetEvent mre;

  public MyClass() {
    mre = new ManualResetEvent(false);
    Data = null;
  }

  public object Data { get; set; }

  void DataSet(object sender, EventArgs e) {
    Console.WriteLine("object Data has been set.");
    mre.Set();
  }

}

Delegates don’t seem to be what I need. An event, maybe? How would I write such an event, if so?

MyClass mc;

void processA() {
  mc = new MyClass();
  mc.Data = GetDataFromLongProcess();
}

Answer 1

private object data;
public object Data {
    get { return data;}
    set {
        if(value != data) {
            data = value;
            OnDataChanged();
        }
    }
}
protected virtual void OnDataChanged() {
    EventHandler handler = DataChanged;
    if(handler != null) handler(this, EventArgs.Empty);
}
public event EventHandler DataChanged;

then hook any code to the DataChanged event. For example:

MyClass mc = ...
mc.DataChanged += delegate {
    Console.WriteLine("new data! wow!");
};