ArrayList tmp = new ArrayList();
tmp.Add(111);tmp.Add(2222);
int[] tmpint = (int[])tmp.ToArray(System.Type.GetType( "System.Int32 "));
将ArrayList转换为整型数组
ArrayList ArrHouseID = new ArrayList();
string strArrHouseID = string.Empty;
strArrHouseID = String.Join(",", (string[])ArrHouseID.ToArray(Type.GetType("System.String")));将ArrayList转换为字符串数组，然后再拼接成字符串。