人民幣大小寫轉換 C#版

using System;

namespace ExpertLib.ChineseSpecial
{
    #region RMBException
    /// <summary>
    /// 人民幣轉換的錯誤
    /// </summary>
    public class RMBException : System.Exception
    {
        public RMBException(string msg)
            : base(msg)
        {
        }
    }
    #endregion

    /// <summary>
    /// 實現將人民幣的數字形式轉換為中文格式，最大支援9兆兆。
    /// </summary>
    public static class RMB
    {
        #region 內部常量
        private static string RMBUppercase = "零壹貳三肆伍陸柒捌玖";
        private static string RMBUnitChar = "元拾佰仟萬拾佰仟億拾佰仟兆拾佰仟萬拾佰仟億拾佰仟兆"; //人民幣整數位對應的標誌
        private const decimal MaxNumber =9999999999999999999999999.99m;
        private const decimal MinNumber = -9999999999999999999999999.99m;
        private static char[] cDelim = { '.' }; //小數分隔標識
        #endregion

        #region Convert
        #region Convert <decimal>
        /// <summary>
        /// 轉換成人民幣大寫形式
        /// </summary>
        /// <param name="digital"></param>
        /// <returns></returns>
        public static string Convert(decimal number)
        {
            bool NegativeFlag=false;
            decimal RMBNumber;

            CheckNumberLimit(number);

            RMBNumber = Math.Round(number, 2);    //將四捨五入取2位小數
            if (RMBNumber == 0)
   {
    return "零元整";
   }
   else if(RMBNumber < 0)  //如果是負數
   {
    NegativeFlag = true;
                RMBNumber = Math.Abs(RMBNumber);           //取絕對值
   }
   else
   {
                NegativeFlag = false;
   }

            string buf = "";                           // 存放返回結果
            string strDecPart = "";                    // 存放小數部分的處理結果
            string strIntPart = "";                    // 存放整數部分的處理結果
            string[] tmp = null;
            string strDigital = RMBNumber.ToString();
           
            tmp = strDigital.Split(cDelim, 2); // 將資料分為整數和小數部分

           
            if (RMBNumber >= 1m) // 大於1時才需要進行整數部分的轉換
            {
                strIntPart = ConvertInt(tmp[0]);
            }

            if (tmp.Length > 1) //分解出了小數
            {
                strDecPart = ConvertDecimal(tmp[1]);
            }
            else  //沒有小數肯定是為整
            {
                strDecPart = "整";
            }
           
            if (NegativeFlag==false) //是否負數
            {
                buf = strIntPart + strDecPart;
            }
            else
            {
                buf = "負"+strIntPart + strDecPart;
            }
            return buf;
        }
        #endregion

        #region Convert <double>
        /// <summary>
        /// 轉換成人民幣大寫形式
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public static string Convert(double number)
        {
            decimal dec;
            try
            {
                dec = System.Convert.ToDecimal(number);
            }
            catch
            {
                throw new RMBException("不能轉成標準的decimal類型:" + number.ToString());
            }
            return Convert(dec);
        }
        #endregion

        #region Convert <float>
        /// <summary>
        /// 轉換成人民幣大寫形式
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public static string Convert(float number)
        {
            decimal dec;
            try
            {
                dec = System.Convert.ToDecimal(number);
            }
            catch
            {
                throw new RMBException("不能轉成標準的decimal類型:" + number.ToString());
            }
            return Convert(dec);
        }
        #endregion

        #region Convert <int>
        /// <summary>
        /// 轉換成人民幣大寫形式
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public static string Convert(int number)
        {
            decimal dec;
            dec = System.Convert.ToDecimal(number);
            return Convert(dec);
        }
        #endregion

        #region Convert <long>
        /// <summary>
        /// 轉換成人民幣大寫形式
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public static string Convert(long number)
        {
            decimal dec;
            dec = System.Convert.ToDecimal(number);
            return Convert(dec);
        }
        #endregion

        #region Convert <string>
        /// <summary>
        /// 轉換成人民幣大寫形式
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public static string Convert(string number)
        {
            decimal dec;
            try
            {
                dec = System.Convert.ToDecimal(number,null);
            }
            catch
            {
                throw new RMBException("不能轉成標準的decimal類型:" + number);
            }
            return Convert(dec);
        }
        #endregion
        #endregion

        #region MaxSupportNumber
        /// <summary>
        /// 支援的最大轉換數
        /// </summary>
        public static decimal MaxSupportNumber
        {
            get
            {
                return MaxNumber;
            }
        }
        #endregion

        #region MinSupportNumber
        /// <summary>
        /// 支援的最小數
        /// </summary>
        public static decimal MinSupportNumber
        {
            get
            {
                return MinNumber;
            }
        }
        #endregion

        #region 內建函式
        #region ConvertInt
        private static string ConvertInt(string intPart)
        {
            string buf = "";
            int length = intPart.Length;
            int curUnit = length;
   
            // 處理除個位以上的資料
            string tmpValue = "";                    // 記錄當前數值的中文形式
            string tmpUnit = "";                    // 記錄當前數值對應的中文單位
            int i;
            for (i = 0; i < length - 1; i++, curUnit--)
            {
                if (intPart[i] != '0')
                {
                    tmpValue = DigToCC(intPart[i]);
                    tmpUnit = GetUnit(curUnit - 1);
                }
                else
                {                   
                    // 如果當前的單位是"萬、億"，則需要把它記錄下來
                    if ((curUnit - 1) % 4 == 0)
                    {
                        tmpValue = "";
                        tmpUnit = GetUnit(curUnit - 1);//
                       
                    }
                    else
                    {
                        tmpUnit = "";
                       
                        // 如果當前位是零，則需要判斷它的下一位是否為零，再確定是否記錄'零'
                        if (intPart[i + 1] != '0')
                        {
                           
                            tmpValue = "零";
                           
                        }
                        else
                        {
                            tmpValue = "";
                        }
                    }
                }
                buf += tmpValue + tmpUnit;
            }

           
            // 處理個位元據
            if (intPart[i] != '0')
                buf += DigToCC(intPart[i]);
            buf += "元";

            return CombinUnit(buf);
        }
        #endregion

        #region ConvertDecimal
        /// <summary>
        /// 小數部分的處理
        /// </summary>
        /// <param name="decPart">需要處理的小數部分</param>
        /// <returns></returns>
        private static string ConvertDecimal(string decPart)
        {
            string buf = "";
            int i = decPart.Length;

            //如果小數點後均為零
            if ((decPart == "0") || (decPart == "00"))
            {
                return "整";
            }

            if (decPart.Length > 1) //2位
            {
                if (decPart[0] == '0') //如果角位為零0.01
                {
                    buf = DigToCC(decPart[1]) + "分"; //此時不可能分位為零
                }
                else if (decPart[1] == '0')
                {
                    buf = DigToCC(decPart[0]) + "角整";
                }
                else
                {
                    buf = DigToCC(decPart[0]) + "角";
                    buf += DigToCC(decPart[1]) + "分";
                }
            }
            else //1位
            {
                buf += DigToCC(decPart[0]) + "角整";
            }
            return buf;
        }
        #endregion

        #region GetUnit
        /// <summary>
        /// 擷取人民幣中文形式的對應位置的單位標誌
        /// </summary>
        /// <param name="n"></param>
        /// <returns></returns>
        private static string GetUnit(int n)
        {
            return RMBUnitChar[n].ToString();
        }
        #endregion

        #region DigToCC
        /// <summary>
        /// 數字轉換為相應的中文字元 ( Digital To Chinese Char )
        /// </summary>
        /// <param name="c">以字元形式儲存的數字</param>
        /// <returns></returns>
        private static string DigToCC(char c)
        {
            return RMBUppercase[c - '0'].ToString();
        }
        #endregion

        #region CheckNumberLimit
        private static void CheckNumberLimit(decimal number)
        {
            if ((number < MinNumber) || (number > MaxNumber))
            {
                throw new RMBException("超出可轉換的範圍");
            }
        }
        #endregion

        #region CombinUnit
        /// <summary>
        /// 合并兆億萬詞
        /// </summary>
        /// <param name="rmb"></param>
        /// <returns></returns>
        private static string CombinUnit(string rmb)
        {
            if (rmb.Contains("兆億萬"))
            {
                return rmb.Replace("兆億萬", "兆");
            }
            if (rmb.Contains("億萬"))
            {
                return rmb.Replace("億萬", "億");
            }
            if (rmb.Contains("兆億"))
            {
                return rmb.Replace("兆億", "兆");
            }
            return rmb;   
        }
        #endregion
        #endregion
    }
}