Get the name of the object the event is registered on in C#

Question

I have subscribed to CollectionChanged event of ObservableCollection<string> m_myCollection like this:

  private ObservableCollection<string> m_myCollection;
  public ObservableCollection<string> MyCollection
  {
     get => m_myCollection;
     set
     {
        m_myCollection= value;
        OnPropertyChanged();
     }
  }

  public ViewModel()
  {
     MyCollection = new ObservableCollection<string>();

     MyCollection.CollectionChanged += OnCollectionChanged;

     MyCollection.Add("Item 1");
  }

  private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
  {
     // How to get the name of the collection here? That is: "MyCollection"
  }

How do I get the name of the collection in the method?

Possible duplicate of [Getting control name for an event](https://stackoverflow.com/questions/7644131/getting-control-name-for-an-event) — Reinstate Monica Cellio, Oct 22 '18 at 14:38
As per that link you need to cast it as a relevant control type so that it has a `name` property. — Reinstate Monica Cellio, Oct 22 '18 at 14:39
@Archer The problem is ObservableCollection does not have a name. — Vahid, Oct 22 '18 at 14:40
You said you want the name, but now you're saying the control type doesn't have a name, so what do you expect to get, and how will it be any use to you? — Reinstate Monica Cellio, Oct 22 '18 at 14:41
@Archer The question is pretty explicit about the expected value that they want to get. "// How to get the name of the collection here? That is: "MyCollection"" — Servy, Oct 22 '18 at 14:42
@Servy He's asking for a variable name, not a control name. In this instance it will be `sender` - I want him to see that himself. — Reinstate Monica Cellio, Oct 22 '18 at 14:44
@Archer Maybe I was a bit ambiguous, but I clearly want the name of the variable as shown in the comment. — Vahid, Oct 22 '18 at 14:49

score 1 · Accepted Answer · answered Oct 22 '18 at 14:40

ObservableCollection instances don't have "names". And any number of variables might hold onto a reference to the collection. There could be none, there could be ten. There's no real "automatic" way of doing this. All you can really do is pass the information around yourself, for example by passing in what you consider the "name" of the collection to be to the handler:

 MyCollection = new ObservableCollection<string>();
 MyCollection.CollectionChanged += (s, e) => HandleCollectionChanged("MyCollection", e);
 MyCollection.Add("Item 1");

Alternatively, you could make your own type of collection, possibly extending ObservableCollection, to give it a Name property that you set in the constructor, and can then read later.

Thank you. I think this way, I will be able to avoid hard-coding it: `MyCollection.CollectionChanged += (s, e) => HandleCollectionChanged(nameof(MyCollection), e);` — Vahid, Oct 22 '18 at 14:48

Get the name of the object the event is registered on in C#

1 Answers1