If you're using an implementation of System.Collections.IEnumerable you can do like following to convert it to a List. The following uses Enumerable.Cast method to convert IEnumberable to a Generic List.
//ArrayList Implements IEnumerable interface
ArrayList _provinces = new System.Collections.ArrayList();
_provinces.Add("Western");
_provinces.Add("Eastern");
List provinces = _provinces.Cast().ToList();
If you're using Generic version IEnumerable, The conversion is straight forward. Since both are generics, you can do like below,
IEnumerable values = Enumerable.Range(1, 10);
List valueList = values.ToList();
But if the IEnumerable is null, when you try to convert it to a List, you'll get
ArgumentNullException saying Value cannot be null.
IEnumerable values2 = null;
List valueList2 = values2.ToList();
Therefore as mentioned in the other answer, remember to do a null check before converting it to a List.
