整数转字符串

        static string TransToString(int value)
        {
            int step = 1000000000;
            char[] results = new char[10];
            int index = 0;
            if (value < 0)
            {
                results[index++] = '-';
                value = 0 - value;
            }
            while (value / step == 0)
                step /= 10;
            while (step!=0&&value / step >= 0)
            {
                if (value / step > 0)
                {
                    results[index++] = (char)('0' + value / step);
                    value = value % step;
                    step /= 10;
                }
                else if (value / step == 0)
                {
                    results[index++] = '0';
                    step /= 10;
                }
            }           
            return new string(results, 0, index);
        }