Converting a List<int> to a comma separated string
List<int> list = ...;
string.Join(",", list.Select(n => n.ToString()).ToArray())
Simple solution is
List<int> list = new List<int>() {1,2,3};
string.Join<int>(",", list)
I used it just now in my code, working funtastic.
List<int> list = new List<int> { 1, 2, 3 };
Console.WriteLine(String.Join(",", list.Select(i => i.ToString()).ToArray()));