c#字典的一个错误使用

using System;using System.Collections.Generic;public class Test{    public static void Main()    {        Dictionary<int, int> data = new Dictionary<int, int>() { { 100, 20 }, { 120, 20 }, { 1293, 30 }};        data.Remove(100);        Console.WriteLine(data.Count);        for (int i = 0; i < data.Count; ++i )             Console.WriteLine(data[i]);    }}

错误：提示未找到指定key
Remove和for不能共存，尽量使用foreach.