给一个字符串，该字符串由0-9组成，要求用一个函数返回字符串中出现最多次数的数字数组。

  public int[] getMaxCount(string str)
        {
            int[] numbers = new int[10];
            foreach (var c in str)
            {
                int num = Convert.ToInt32(c.ToString());
                numbers[num]++;
            }
            List<int> result = new List<int>();
            for (int i = 0; i < numbers.Length; i++)
            {
                if (numbers[i] == numbers.Max())
                {
                    result.Add(i);
                }
            }
            return result.ToArray();
        }

　　

   public int[] getMaxCount(string str)
        {
            var strGroupBy = str.GroupBy(c => c).Select(d => new { key = d.Key, count = d.Count() }).OrderByDescending(d => d.count);
            return strGroupBy.Where(d => d.count == strGroupBy.FirstOrDefault().count).Select(d => Convert.ToInt32(d.key.ToString())).ToArray();

        }