Question

foreach (var shotItem in Invadershots)// it points to me to there and doesnt allow me to loop.."{"Collection was modified; enumeration operation may not execute."}"
{
  shotItem.Move();// it happens when this simple method called (which actually checks some bool..if the shot was out of the winform).
  if (shotItem.removeShot)
  {
        Invadershots.Remove(shotItem);
  }
}

Could it be because i change the List items simultaneously?
How can i prevent that error from occurring?

Answer 1

You cannot alter a collection whilst enumerating across it. Create a clone of the collection and alter that.