Question

I am adding items to a ListBox like so:

myListBox.Items.addRange(myObjectArray); 

and I also want to select some of the items I add by the following:

foreach(MyObject m in otherListOfMyObjects)  {     int index = myListBox.Items.IndexOf(m);     myListBox.SelectedIndices.Add(index); } 

however index is always -1.

Is there a different way to get the index of an object in a ListBox?

Answer 1

You should make sure that MyObject overrides Equals(), GetHashCode() and ToString() so that the IndexOf() method can find the object properly.

Technically, ToString() doesn’t need to be overridden for equality testing, but it is useful for debugging.