C# List轉換成字符串 按指定的字符分隔

var stringExcept = result.Except(compareList).ToList(); //兩個List獲取差集
string notExistValue = String.Join(",", stringExcept.ToArray());//數組轉換成string用逗號分隔

轉自： http://www.javashuo.com/article/p-ohpjebcs-ds.html