C#转换英文大写（两位小数）

string[] arr1 = new string[4] {"", " THOUSAND", " MILLION", " BILLION"};
    string[] arr2 = new string[10] {"ZERO", "TEN", "TWENTY", "THIRTY", "FORTY", "FIFTY", "SIXTY", "SEVENTY", "EIGHTY", "NINETY"};
    string[] arr3 = new string[10] {"ZERO", "ONE", "TWO", "THREE", "FOUR", "FIVE", "SIX", "SEVEN", "EIGHT", "NINE"};
    string[] arr4 = new string[10] { "TEN", "ELEVEN", "TWELVE", "THIRTEEN", "FOURTEEN", "FIFTEEN", "SIXTEEN", "SEVENTEEN", "EIGHTEEN", "NINETEEN" };

# region 英文數字翻譯
    private string Translate(string num)
    {

         double len=num.Length;
         int i,j=0;
         string strRet="";
         double cols1=Math.Ceiling(len/3);
         int cols = SysConvert.ToInt32(cols1);
         double    first1=len-cols1*3;
         int first = SysConvert.ToInt32(first1);

         for(i=SysConvert.ToInt32( first);i<len;i+=3)
         {
             string num3 = "";
                     ++j;
          if(i>=0)
          {
              if (i + 3 < len)
              {
                  num3 = num.Substring(i, 3);
              }
              else
              {
                  num3 = num.Substring(i,SysConvert.ToInt32(len)-i);
              }
          }
            else
              {
                  num3 = num.Substring(0, SysConvert.ToInt32(first) + 3);
              }
         string strEng=English(num3);
          if(strEng!="")
          {
           if(strRet!="")
               strRet+="," ;

           strRet += English(num3) + arr1[SysConvert.ToInt32(cols) - j];
          }
         }
         return strRet;

    }
    private string English( string num)
{
string strRet="";
if((num.Length==3)&&(num.Substring(0,3)!="000"))
{
if((num.Substring(0,1)!="0"))
{
   strRet+=arr3[SysConvert.ToInt32( num.Substring(0,1))]+" HUNDRED";
   if(num.Substring(1,2)!="00")
       strRet+=" AND ";
}
num=num.Substring(1);
}
     if((num.Length==2))
     {
      if((num.Substring(0,1)=="0"))
      {
          num = num.Substring(1);
      }
      else if ((num.Substring(0, 1) == "1"))
      {
          strRet += arr4[SysConvert.ToInt32(num.Substring(1, 1))];
      }
      else
      {
          strRet += arr2[SysConvert.ToInt32(num.Substring(0, 1))];
          if (num.Substring(1, 1) != "0")
           strRet+="-";
       num = num.Substring(1);
      }
     }
if ((num.Length == 1) && (num.Substring(0, 1) != "0"))
{
     strRet += arr3[SysConvert.ToInt32(num.Substring(0, 1))];
}
return strRet;
}
    #endregion