完成一个函数：
函数功能：找到一个字符串中最多连续字符串(区分大小写）
如何确定一个子字符串是否连续呢？

static void Main(string[] args)
        {
            string str = "ddsdssdsdsgfgfgggggdfaaafddsadsad";

            int resultNum = 0;         // 最多的连续字符的数量
            char resultChar = ' ';     // 最多的连续字符

            int tempNum = 0;           // 当前连续字符的数量
            char tempChar = ' ';       // 当前连续字符

            for (int i = 0; i < str.Length; i++)
            {
                if (tempChar != str[i]) // 字符不同，说明已经不连续
                {
                    if (resultNum < tempNum) // 记录最长的连续字符数量和字符
                    {
                        resultChar = tempChar;
                        resultNum = tempNum;
                    }

                    tempChar = str[i];
                    tempNum = 1;
                }
                else
                {
                    tempNum++;
                }
            }
            // 输出连续的字符
            for (int j = 0; j < resultNum; j++)
            {
                Console.Write(resultChar);
            }

            Console.ReadKey();
        }

恩恩，多谢