数字金钱大小写转换

  /// <summary>
    /// 转换人民币大小金额
    /// </summary>
    /// <param name="num">金额 </param>
    /// <returns>返回大写形式 </returns>
    public static string NumToCNum(decimal num)
    {
      string str1 = "零壹贰叁肆伍陆柒捌玖";            //0-9所对应的汉字
      string str2 = "万仟佰拾亿仟佰拾万仟佰拾元角分"; //数字位所对应的汉字
      string str3 = "";    //从原num值中取出的值
      string str4 = "";    //数字的字符串形式
      string str5 = "";  //人民币大写金额形式
      int i;    //循环变量
      int j;    //num的值乘以100的字符串长度
      string ch1 = "";    //数字的汉语读法
      string ch2 = "";    //数字位的汉字读法
      int nzero = 0;  //用来计算连续的零值是几个
      int temp;            //从原num值中取出的值

      num = Math.Round(Math.Abs(num), 2);    //将num取绝对值并四舍五入取2位小数
      str4 = ((long)(num * 100)).ToString();        //将num乘100并转换成字符串形式
      j = str4.Length;      //找出最高位
      if (j > 15) { return "溢出"; }
      str2 = str2.Substring(15 - j);  //取出对应位数的str2的值。如：200.55,j为5所以str2=佰拾元角分

      //循环取出每一位需要转换的值
      for (i = 0; i < j; i++)
      {
        str3 = str4.Substring(i, 1);          //取出需转换的某一位的值
        temp = Convert.ToInt32(str3);      //转换为数字
        if (i != (j - 3) && i != (j - 7) && i != (j - 11) && i != (j - 15))
        {
          //当所取位数不为元、万、亿、万亿上的数字时
          if (str3 == "0")
          {
            ch1 = "";
            ch2 = "";
            nzero = nzero + 1;
          }
          else
          {
            if (str3 != "0" && nzero != 0)
            {
              ch1 = "零" + str1.Substring(temp * 1, 1);
              ch2 = str2.Substring(i, 1);
              nzero = 0;
            }
            else
            {
              ch1 = str1.Substring(temp * 1, 1);
              ch2 = str2.Substring(i, 1);
              nzero = 0;
            }
          }
        }
        else
        {
          //该位是万亿，亿，万，元位等关键位
          if (str3 != "0" && nzero != 0)
          {
            ch1 = "零" + str1.Substring(temp * 1, 1);
            ch2 = str2.Substring(i, 1);
            nzero = 0;
          }
          else
          {
            if (str3 != "0" && nzero == 0)
            {
              ch1 = str1.Substring(temp * 1, 1);
              ch2 = str2.Substring(i, 1);
              nzero = 0;
            }
            else
            {
              if (str3 == "0" && nzero >= 3)
              {
                ch1 = "";
                ch2 = "";
                nzero = nzero + 1;
              }
              else
              {
                if (j >= 11)
                {
                  ch1 = "";
                  nzero = nzero + 1;
                }
                else
                {
                  ch1 = "";
                  ch2 = str2.Substring(i, 1);
                  nzero = nzero + 1;
                }
              }
            }
          }
        }
        if (i == (j - 11) || i == (j - 3))
        {
          //如果该位是亿位或元位，则必须写上
          ch2 = str2.Substring(i, 1);
        }
        str5 = str5 + ch1 + ch2;

        if (i == j - 1 && str3 == "0")
        {
          //最后一位（分）为0时，加上“整”
          str5 = str5 + '整';
        }
      }
      if (num == 0)
      {
        str5 = "零元整";
      }
      return str5;
    }

  }