deciaml percent = 0.123456789123456789M;
//12345.ToString("p"); 生成 1,234,500.00%
string q1 = percent.ToString("P"); //12.35%;自动四舍五入，百分数，千位分隔，自动两个小数
string q2 = percent.ToString("P0"); //12%；P后边跟数字，代表精度。
string q3 = percent.ToString("P1"); //12.3%；
string q4 = percent.ToString("P2"); //12.35%；
string q5 = percent.ToString("P3");
string q6 = percent.ToString("P4");
string q7 = percent.ToString("P5");
string q8 = percent.ToString("P6");

decimal percent =0.24015M;
string q9 = percent.ToString("0.##%"); //得到 "24.02%"
//##个数表示保留的小数位数（必要时四舍五入）

#region 小数变百分比
        /// <summary>
        /// 小数变百分比
        /// </summary>
        /// <param name="temp">要转化为百分比的原数字</param>
        /// <param name="length">小数点后有几位数字</param>
        /// <returns></returns>
        public static string GetPercent(decimal Number)
        {
            int length = GetPointNumber(Number);
            if (length >= 2)
            {
                string temp = "P" + (length - 2).ToString();
                return Number.ToString(temp);
            }
            else
               return ((int)(Number*100)).ToString() + "%";
        }
        #endregion

        #region 获取小数点后有几位小数
        public static int GetPointNumber(decimal Number)
        {
            var s = Number.ToString();
            return s.Length - s.IndexOf('.') - 1;
        }
        #endregion