人民币大小写转换

using System;
using System.Text;
using System.Text.RegularExpressions;

namespace HKH.Common
{
 /// <summary>
 /// 人民币大小写格式转换
 /// </summary>
 /// <remarks> Create By Lwt on 2006/09/23
 /// </remarks>
 public class clsRMB
 {
  private clsRMB()
  {
  }

  #region 格式化

  /// <summary>
  /// 格式化（大写转小写）
  /// </summary>
  /// <param name="strRMB"></param>
  /// <returns></returns>
  public static double Format(string strRMB)
  {
   try
   {
    //正则表达式，验证第一位是否阿拉伯数字，确定转换格式
    //1.5亿----混写格式
    if(Regex.IsMatch(strRMB,"^\\d"))
    {
     //去掉元单位
     strRMB = Regex.Replace(strRMB,"元|圆","");
     char temp = strRMB[strRMB.Length - 1];
     if (temp == '万' || temp == '萬' || temp == '亿')
     {
      return Convert.ToDouble(strRMB.Substring(0,strRMB.Length - 1)) * Math.Pow(10,GetExp(temp));
     }
     else
     {
      return Convert.ToDouble(strRMB);
     }
    }
    //壹亿伍千万-----大写格式
    else 
    {
     return Eval(strRMB);
    }

   }
   catch
   {
    return -1;
   }
  }

  /// <summary>
  /// 格式化（小写转大写）
  /// </summary>
  /// <param name="numRMB"></param>
  /// <returns></returns>
  public static string Format(double numRMB)
  {
   try
   {
    if( 0 == numRMB)
     return "零元整";

    StringBuilder szRMB = new StringBuilder();

    //乘100以格式成整型，便于处理
    ulong iRMB = Convert.ToUInt64(numRMB * 100);

    szRMB.Insert(0,ToUpper(Convert.ToInt32(iRMB % 100),-2));
  
    //去掉原来的小数位
    iRMB = iRMB / 100;

    int iUnit = 0;

    //以每4位为一个单位段进行处理，所以下边除以10000
    while(iRMB != 0)
    {
     szRMB.Insert(0,ToUpper(Convert.ToInt32(iRMB % 10000),iUnit ));
     iRMB = iRMB / 10000;
     iUnit += 4;
    }
      
    string strRMB = szRMB.ToString();
    
    //格式修正
    strRMB = Regex.Replace(strRMB,"零+","零");
    strRMB = strRMB.Replace("元零整","元整");
    strRMB = strRMB.Replace("零元","元");

    return strRMB.Trim('零');
   }
   catch
   {
    return "";
   }
  }

  #endregion

  #region 私有方法

  /// <summary>
  /// 计算表达式（大写表达式求值）
  /// </summary>
  /// <param name="strRMB"></param>
  /// <returns></returns>
  private static double Eval(string strRMB)
  {
   try
   {
    if (null == strRMB )
     return 0;

    strRMB = Replace(strRMB,false);

    if ("" == strRMB)
     return 0;

    #region 利用位权进行计算

    //基础指数
    int basicExp = 0;
    //当前指数
    int currExp = 0;

    double numRMB = 0;

    for(int i = strRMB.Length - 1; i > -1 ; i --)
    {
     char temp = strRMB[i];

     if (temp == '元' || temp == '万' || temp == '亿' || temp == '圆' || temp == '萬' )
     {
      basicExp = GetExp(temp);
      currExp = 0;

      continue;
     }
     else
     {
      if(Regex.IsMatch(temp.ToString(),"^\\d"))
      {
       numRMB = numRMB + Convert.ToInt32(temp.ToString()) * Math.Pow(10,(basicExp + currExp));
      }
      else
      {
       currExp = GetExp(temp);
      }

     }
    }

    #endregion

    return numRMB;
   }
   catch
   {
    return -1;
   }
  }

  /// <summary>
  /// 计算表达式（小写数值求大写字符串）
  /// </summary>
  /// <param name="numRMB"></param>
  /// <param name="iUnit"></param>
  /// <returns></returns>
  private static string ToUpper(int numRMB,int iUnit)
  {
   try
   {
    if( 0 == numRMB )
    {
     if (iUnit == -2)
     {
      return "整";
     }
     
     if (iUnit == 0)
     {
      return "元";
     }

     return "零";
    }

    StringBuilder szRMB = new StringBuilder();

    string strRMB = "";
    
    #region 对角/分做特殊处理

    if (iUnit == -2)
    {
     int jiao = numRMB / 10;
     int fen = numRMB % 10;

     if (jiao > 0)
     {
      szRMB.Append(jiao);
      szRMB.Append(GetUnit(-1));

      if ( fen > 0)
      {
       szRMB.Append(fen);
       szRMB.Append(GetUnit(-2));
      }
     }
     else
     {
      szRMB.Append(fen);
      szRMB.Append(GetUnit(-2));
     }

     return Replace(szRMB.ToString(),true);
    }

    #endregion

    #region 以下为整数部分正常处理

    strRMB = numRMB.ToString("0000");

    //前一位是否是0
    bool hasZero = false;
    
    for ( int i = 0; i < strRMB.Length; i++ )
    {
     //只有四位，最高位为‘千’，所以下边的3-i为单位修正
     if ( ( 3-i ) > 0)
     {
      if( '0' != strRMB[i] )
      {
       szRMB.Append(strRMB[i]);
       szRMB.Append(GetUnit( 3-i ));
       hasZero = false;
      }
      else
      {
       if( !hasZero )
        szRMB.Append(strRMB[i]);

       hasZero = true;
      }
     }
     //最后一位，特别格式处理
     //如最后一位是零，则单位应在零之前
     else
     {
      if( '0' != strRMB[i] )
      {
       szRMB.Append(strRMB[i]);
       szRMB.Append(GetUnit( iUnit ));
       hasZero = false;
      }
      else
      {
       if (hasZero)
       {
        szRMB.Insert(szRMB.Length - 1,GetUnit( iUnit ));
       }
       else
       {
        szRMB.Append(GetUnit( iUnit ));
        szRMB.Append(strRMB[i]);
       }
      }
     }
    }

    //转换大写后返回
    return Replace(szRMB.ToString(),true);

    #endregion
   }
   catch
   {
    return "";
   }
  }

  /// <summary>
  /// 将中文大写换成阿拉伯数字
  /// </summary>
  /// <param name="strRMB"></param>
  /// <param name="toUpper">true--转换为大写/false--转换为小写</param>
  /// <returns></returns>
  private static string Replace(string strRMB,bool toUpper)
  {
   if(toUpper)
   {
    strRMB = strRMB.Replace("0","零");
    strRMB = strRMB.Replace("1","壹");
    strRMB = strRMB.Replace("2","贰");
    strRMB = strRMB.Replace("3","叁");
    strRMB = strRMB.Replace("4","肆");
    strRMB = strRMB.Replace("5","伍");
    strRMB = strRMB.Replace("6","陆");
    strRMB = strRMB.Replace("7","柒");
    strRMB = strRMB.Replace("8","捌");
    strRMB = strRMB.Replace("9","玖");
   }
   else
   {
    strRMB = strRMB.Replace("零","0");
    strRMB = strRMB.Replace("壹","1");
    strRMB = strRMB.Replace("贰","2");
    strRMB = strRMB.Replace("叁","3");
    strRMB = strRMB.Replace("肆","4");
    strRMB = strRMB.Replace("伍","5");
    strRMB = strRMB.Replace("陆","6");
    strRMB = strRMB.Replace("柒","7");
    strRMB = strRMB.Replace("捌","8");
    strRMB = strRMB.Replace("玖","9");
   }
   return strRMB;
  }

  /// <summary>
  /// 获取单位名称
  /// </summary>
  /// <param name="iCode"></param>
  /// <returns></returns>
  private static string GetUnit(int iCode)
  {
   switch(iCode)
   {
    case -2:
     return "分";
    case -1:
     return "角";
    case 0:
     return "元";
    case 1:
     return "拾";
    case 2:
     return "佰";
    case 3:
     return "仟";
    case 4:
     return "萬";
    case 8:
     return "亿";
    default:
     return "";
   }
  }

  /// <summary>
  /// 获取位权指数
  /// </summary>
  /// <param name="cUnit"></param>
  /// <returns></returns>
  private static int GetExp(char cUnit )
  {
   switch(cUnit)
   {
    case '分':
     return -2;
    case '角':
     return -1;
    case '元':
    case '圆':
     return 0;
    case '十':
    case '拾':
     return 1;
    case '百':
    case '佰':
     return 2;
    case '千':
    case '仟':
     return 3;
    case '万':
    case '萬':
     return 4;
    case '亿':
     return 8;
    default:
     return 0;
   }
  }

  #endregion

 }
}