Question

What’s the proper way to do this?

  foreach(Object obj in ObjectList<Object>)
   {
      Object changedObject= GetInfo(obj);
      obj=changedObject; //no good
      obj.prop1 = changedObject.prop1; //ok?
      obj.prop2 = changedObject.prop2; //ok?
      better way?
    }

Answer 1

Use a for loop instead:

for (int i = 0; i < list.Count; i++)
{
    Object changedObject = GetInfo(list[i]);
    list[i] = changedObject;
}

You could also use LINQ, and append .ToList() if you need a list instead of an IEnumerable<T>:

var query = result.Select(o => GetInfo(o));