public static void TestRemove() {            string[] str = { "1", "2", "d", "x" };            List
    
      list = new List
     
      (str);            #region has error            for (int i = 0; i < list.Count; i++)            {                Console.WriteLine(list[i]);                Console.WriteLine("Result:" + i + ":" + i / 2);                if (i % 2 == 0)                {                    list.Remove(list[i]);                }            }             #endregion            Console.WriteLine("============================================");            list = new List
      
       (str);            for (int i = list.Count-1; i >= 0; i--)            {                Console.WriteLine(list[i]);                Console.WriteLine("Result:" + i + ":" + i / 2);                if (i % 2 == 0)                {                    Console.WriteLine(string.Format(" delete .index:{0} value:{1}",i,list[i]));                    list.Remove(list[i]);                 }            }        }
      
     
    

output:

1

Result:0:0

d

Result:1:0

x

Result:2:1

============================================

x

Result:3:1

d

Result:2:1

delete .index:2 value:d

2

Result:1:0

1

Result:0:0

delete .index:0 value:1